6 YO Male cat with crystals.

I have a 6 yr old male cat that I love and he is miserable.  Last night I was late from work, so he ate his 1/2 can wet fancy feast so fast and then acted so weird. He was hissing at the kitten who is 6 months old any time she walked near her. Then she looked like she was stuck in a weird position, almost squatting on the living room floor. Long night but she urinated drops everywhere so I took her to the Pet hospital this morning and he manually emptied her bladder and said there were two crystals in there.  He gave him pain meds, fluids and an antibotic shot and I brought him home.  He doesnt seem any better. goes to the litter box and sits for several mins and drops are just coming out.  I gave him about a tablespoon of food and added water to it.  Now he is just laying on the floor on his side.  I never slept last night so I have the kitten in my room with me and hoping that he'll just relax tonight and let the meds work. (this happened in March and I cut out a lot of his dry but I think I slowly added it back in so that will be over with now).  Sorry this is so long but Im nervous.  They said if he doesnt urinate a stream by morning they will have to do more. Anyone have this happen before? I had to put down my 17 yo cat last year and Im still hurting so I think Im more scared than I usually would be. Thanks!!

Do you have an emergency vet you can call?  If not, call the vet you took him to and see if there's a message on their answering machine with instructions for after hours emergencies.  You really need some help.  Do you know how to syringe feed?  You need to assist feed and give him water via syringe as well.
 

I would call the vet's office or an emergency clinic. If he has eaten a little food, I don't think I would try to get much more in him just in case he has to go under anesthesia. But I would definitely start making some calls.

I called the vet this morning and they agreed with the Pet ER from yesterday.  Told me to feed him the food they gave me and add water to it. We are going to watch him another day or two unless it gets worst.   He seems a little better tonight, still sitting in the litter box for several minutes at a time but little coming out.  I gave him pain medicine this afternoon (tramadol 1/4 pill of 50mg) He's licking the area like crazy but he's chubby so its hard for him. I feel so bad for him.