2 year old female sick for 4 days HELP PLEASE

My baby, Piper, a 2 year old female (spayed) cat suddenly became VERY different on Monday. Last week (3/16 & 3/17) she was acting distant and a little be lethargic. We suspect it was her who had vomited a liquidy clearish fluid about 3 times over the previous weekend. I say suspect, because we also have a 6 month old kitten, but she is and has been acting normal. At any rate, Piper bounced back on Wednesday and was acting like her normal, happy-go-lucky self. . . . . But suddenly on Monday of this week (3/23) we noticed she had not moved from her "hiding spot" on a shelf with a cushion on it under our kitchen island. So of course we started to pay a lot more attention to her. Since then we've observed the following:
-will not get up to walk, period.

-will eat a treat if you bring it to her, but will not eat her hard food if you bring it to her. 

-would not drink water, period.

-Obviously not getting up to go to the litter box, but also will not relieve herself anywhere. Not even where she is laying or right outside of her bed.

-Growls if you go to touch her. My fiance says it's when he is touching her back legs, but I tend to disagree. I have picked her up and put her on all four paws and it seems to me that something is up with the FRONT of her body. Her front legs don't seem to be working like they usually do. She CAN walk, but it doesn't seem very stable to me. 
-She is, again, extremely lethargic. Barely lifts her head when you walk in or are loving on her. But if you get the laser pointer out, she will perk up. It's almost like you can see that she wants to play, but makes the decision that she can't.

At first I thought maybe a UTI due to the fact that I changed litter about 2 or 3 weeks ago. I have made sure that I changed back to the original litter and I have been cleaning the box obsessively. We did also change food from something (I can't remember what it was) to iams indoor proactive health. 

Again, this has been going on since at the very least, Monday. Wednesday night I started to freak out and called the emergency vet. They advised that it probably wasn't necessary to bring her in since I had already scheduled an appointment with the regular vet for Thursday at noon.
We brought her in to the vet yesterday (3/26) and she ended up urinating FINALLY in her carrier right before they took her back to get blood work. Good that she did that, but not good because they were then unable to get a urine sample. Her temp was almost 105 F upon arrival at the office, but the doctor suspected that it could possibly be up due to stress.

So they gave her IV fluids, of course she was dehydrated. Ran a bunch of blood work, but everything has come back normal so far. They did send off some to an outside lab that hopefully we will have back today. They only thing that was out of the normal was an elevated white blood cell count. The Doctor is stumped and that is what is freaking me out right now. He sent her home with an anti-inflammatory as well as an antibiotic to try to be proactive while we are waiting for answers.

When we got her home yesterday, gave her a small bowl of water and she went to town drinking it! It made me so happy, but again, she hasn't gone to the bathroom or anything. 

We were sent home with Critical Care soft food that she, apparently, loved and chowed down on yesterday while at the vet. I tried to give her some this morning and she wanted nothing to do with it. Same with water.

My baby is only 2 years old and this is ridiculous! I don't know what's wrong with her and I don't want to lose her. It's awful watching her lay in misery. Does anyone by chance have any ideas or had this kind of experience???? 

This really could be anything.  The elevated white cell count could be an infection of some sort.  Kitties tend to hide illness until they can't hide it any longer so they appear to go from being fine to being very sick quickly.  Your kitty does need food to avoid a condition unique to felines called fatty liver or hepatic lipidosis.  I assume they gave you Hill's A/D and yes cats tend to like it.  I would try some tricks like warming it to increase the smell and trying to feed her by hand to get her started.  If this doesn't work then you may have to syringe feed her.  You can get the syringes at pet stores or your vet.  The main thing Is to go slow and don't shoot the food straight back in her throat.  Use the side of her mouth and let her swallow it on her own.

Sorry I can't suggest anything except don't be afraid to call the vet. They may be able to suggest something. Good luck x

I'm wondering if she doesn't have some kind of urinary tract infection or blockage. I think if at all possible a urine sample should be obtained. Has she had a bowel movement at all, maybe she is extremely constipated? All the luck, I'll pray that everything turns out alright.

Update: At 11:15 I called the vet because I was near tears so worried and couldn't concentrate on my job. I told the lady that I was calling to see what time we should expect to have the blood work back from yesterday. She told me that I had called at the perfect time because the Doctor had just given her Piper's chart to have her call to see how she was doing overnight and today. (Blood work isn't back yet) I let her know the details that I told all you guys about with her drinking and everything last night and then going right back to the same. The doctor was in surgery, but the receptionist told me she was going to go talk to her and would call me right back. I tell you what, she DID call me right back! I was thoroughly surprised. At any rate, the doctor asked that I bring her back in right away. Thank goodness I work and live less than 2 miles away.

Took her back in and she was a bit more alert on the ride there, but probably just because she was freaking out. 

Fiance and I bickered a bit on the phone after I told him I dropped her off. We already spent close to $400 yesterday and today they "hospitalized" her so they can observe her and make some decisions once the doctor is out of surgery. God only knows how much all of this is going to cost. He's right, we can't put our selves further into debt when we don't even know if she's going to make it. But I just can't rationalize NOT spending the money right now until we at least know what's wrong. 

@Di and Bob: The vet said he wasn't really convinced it was either of those things. They were actually the first two things I thought was going on. No bowel movement that we know of. I'm assuming she isn't going to the bathroom at all because she's staying pretty much in the same spot all the time. But I'm not sure if she attempts to make it to the litter box or not while we're at work. 

@Denice: The vet actually commented on the hepatic lipidosis yesterday and said that maybe the few treats she was eating and the little bit of dry food that she at that I just put on her cushion were keeping that from happening. All her stuff came back normal. As far as her WBC being up, I figured as much with an infection, I just wish I knew what kind!

So now I guess it's just waiting game. I hate this. And I hate that I've gotten on all these threads like a crazy person and keep reading about all the sweet babies that ended up dying. I've already lost two cats this year, my 17 year old and my 19 year old. They both lead long-full lives, but losing one this young??? I just don't get it!

Don't worry about acting like a 'crazy person'. we all would in your situation. This site is here to offer emotional support too, so rant and cry all you want, we'll understand and try to help. I wish SOMEONE could come on and say, Hey, that sounds like MY cat, I know what it is!. I'll keep my fingers crossed. I'll pray for you both, all the luck!

UPDATE: so I just wanted to make sure that I didn't just let this thread stay open without updating....... The Vet decided that they wanted to keep Piper over night on Friday. They were having a very hard time getting urine from her and an even harder time trying to get her temp to come down. Hard as it was to leave her, I knew it was probably the best for her. I have to say one thing...... The Vet that we recently found that is LITERALLY about a mile from our house is pretty awesome. Every single person in there loves on the animals and they were doing an AWESOME job trying to keep this whole thing affordable for me while still making sure Piper was being taken care of. 

Anyways, they got the FeLV and FIV testing back and all was negative. I really assumed it would be, but I had started to get worried. After she finally got her xrays the diagnosis was determined to be Pancreatitis. When I picked her up on Saturday, her temp was still up, but she had finally pooped and she ate her dry food over the night.  They gave me two different types of soft food for her to try. One with more fiber and stuff and one that is lower fat. We're also going to try her on Pepcid before she eats. Which that should be interesting because we have to just leave food out for the girls. They won't do the feeding schedule thing lol.

The best part about all of this is that, all of a sudden yesterday, Piper just started acting almost 100% like herself! She wasn't going to her hiding spot to sleep! OF course, she was laying around, but she's a cat! But she was laying in her usual "turkey pose" is  what I like to call it, instead of on her side like a limp noodle.

If everyone could just keep the good vibes coming our way! I really don't want a relapse and i don't ever want to see my girl go thru any of that again. Not to mention, my wallet can't really handle it. 

Thank You all again for your thoughts and prayers