Cat acting 100% normal except refusing to eat

Bear with me, this is long because I'm trying to include any pertinent details because I'm stumped:

River is an almost 3 year old female cat. Fixed. Up to date on vaccinations. One other cat (same age and they have been together their whole lives) in the house - both are strictly indoor cats. Both are raw fed - primarily ground but also supplemented with some boneless meat chunks and chicken wings (3-5x a month for each of those with no real schedule - usually as trimmings/extra wings/drumsticks etc from when I'm making dinner.) They get a variety - chicken, turkey, duck, rabbit, pork, and occasionally quail, goose, and fish. She is food obsessed - exceptionally so. (No joke, if she were a person I'd have checked her into rehab for an eating disorder). It necessitates a schedule of 3 feedings/day of measured amounts otherwise she'll just eat until she pukes and then keep eating. No worms/parasites or any other health problems that could cause that. She's just always been that way and both the vet and I chock it up to spending the entire first year of her life in a shelter fed entirely in a group setting. I can always tell if I haven't cleaned the kitchen well enough (or if the kids have left something where she can get it) because she throws up almost instantly if she eats anything with corn or wheat in it.

That being said she seems to have suddenly become "picky". Mid October she stopped eating for 24 hours, threw up multiple times, and was over all just acting sick. I took her to the vet because refusing food is a big red flag for her (see above). Vet couldn't find anything wrong with her, gave her an anti-nausea shot, a tube of probiotics, and sent us home. For the first 24-36 hours after the shot she was fine and ate normally. Then she was back to refusing food... selectively.  At first I was sure she was just being picky and holding out for "the good stuff" - commercial canned food (sometimes given as treats), boneless meat chunks, chicken legs etc... because she still inhales those like normal (no sign of her mouth hurting etc) but now, a month later, I'm starting to wonder if something else is up. She'll eat fairly normally when it's a treat or pork (or at least she did last time pork was in rotation, a week ago) but she is flat out refusing to eat both chicken and turkey. We've gotten her to eat some (about 1/2 to 2/3 the normal amount) by mixing in a little canned tuna for the past week but for the last 36 hours even that hasn't worked. The meat is still good (the other cat still tucks in and gobbles it down like it's 5 star dining). I wondered if it might be the additives that I put in the ground raw (fish oil, vitamin E, light salt, and taurine) so yesterday I opened up a chub of chicken (since that's what she is currently refusing I wanted to do as direct a comparison as possible) and gave her some of that. She ate it. Zero hesitation. No "woe is me having to eat this food" moping etc... so I figured I'd found the problem.

Except that then she didn't eat dinner, breakfast, or lunch... and absolutely nothing has changed about the food.  She is still acting normal - she still snuggles, plays (she and my two year old spent a good 30 minutes playing fetch this morning) and tries to steal our food/licks up any crusted food bits the toddler might have left on his chair. She still acts normal except she's not eating... and after a month the reduced caloric intake is starting to show. She's lost about a pound (normally around 9lbs, now she's closer to 8).

I'm not sure what I'm looking for here... if she's just being picky I don't want to take her back to the vet both because money is a bit more limited this year than normal and because she hates being transported/taken to the vet - hates in a "spend the three days following a visit hiding down the front of mommy's (that's me) shirt shaking and meowing pitifully" sort of way. But if she's sick I don't want her suffering/getting worse. I've run out of containers to portion the chubs of ground cat food into so I'll pick up some more and see if she'll eat pork (which was the last thing, sans the chicken yesterday, that she ate like normal) and I'll pick up a few cans of cat food as last ditch effort to get her to eat something. If she refuses both I guess we're back to the vet (sigh) but I was hoping that someone might have some insight or words of encouragement or...

I've had cats my whole life and dealt with a host of health problems (infections, cancer, kidney failure, broken bones, parasites etc) but this is completely new to me.

A partial blockage in her digestive tract? A newly-developed allergy? My allergy cat's allergies really exploded when he hit about 3-4 years old. Sorry, that's all I have to suggest. 

I used to feed raw until two of mine went on a raw strike and I swear they would have starved themselves to death rather than eat raw.  Period.  So I opened up some canned food that I kept for emergencies (like when we needed to have someone come over and feed them), and guess what?  They ate! 

So, have you given that a try?  Will she eat anything other than the raw food and tuna?  Even try some Fancy Feast CLASSICS, which most cats cannot resist.  Or how about treats?  Can you get her to eat any of those.  Do you have any Wholelife or Purebites freeze dried meats around?  If she absolutely won't touch anything that is either completely new to her, or is a favorite TREAT, not a meal, then I would definitely get her in to be seen ASAP. 

She could even be constipated, have a bad hairball blocking the way, other blockage, some sort of infection, there are many reasons why cats don't eat,but this could turn into Hepatic Lipidosis if she doesn't eat soon, and THAT is definitely something you do not want.

Thank you both for you thoughts! After my initial post I dug through the pantry and found a lowly can of cat food which I promptly opened up and offered to her. She of course inhaled it and has been eating (canned food) normally since then. That combined with her normal behavior and her desire to still eat ALL. THE. FOOD. (minus, of course, raw ground chicken or turkey - everything else is game!) I'm thinking she likely was sick back in October (do cats get the stomach flu? Because if she'd been one of my kids that's what I would have "diagnosed" it as.) then because of a suppressed appetite fell into  that cycle of needing to eat but not wanting to eat.  Add in some selective pickiness - "I don't want this, I want pork/duck/treats!" and...

 Now that I'm not freaking out over her lack of eating and looking back over the last couple of months and they have been eating more chicken/turkey than is typical (largely because they're the cheapest... I'm still trying to recover from unexpectedly having to replace my HVAC) and I suspect she just got sick of them (but not the cuts of said meat because those are *treats*).

Right now my plan is to keep her on canned food for a couple of weeks and than transition into raw like we were/are starting all over again.

So glad she is eating again, even though it isn't the preferred food of choice.  Cats can be so frustrating sometimes.  (I say this as I sit with a full bowl of food next to me, and ONE cat who is whining because he's hungry, but doesn't want what is being served ...AGAIN ,       OH!  he must have felt my frustration, because he just dove in )

When my cat had her eating issues, they did the same - gave her antinausea medicine. They said that if she got nauseous off a certain food before, when she goes to eat it again, the food then makes her nauseated and she then snubs it.

I don't know much about raw feeding. I tried it with my late cat and she refused it. The holistic vet suggested cooking it fully and reducing slowly how cooked it is. Since your cats are used to raw, maybe try partially cooking it for her. Heat will make it more aromatic which in turn will trigger her appetite.

How's her blood work? Everything look normal?