whats wrong with my cat?

My cat has hyperthyroidism and is on tapazole. After being away for about 2 days she has not been using the bathroom in places other than her litter boxes. now she is trying to use the bathroom but it seems like she cant. she sits for about thirty minutes and only clear liqhid comes out. she has also been awfully quiet. as far as i know she has no other problems, but her bathroom habits have been out of wack before (before being diagnosed with hyperthyroidism). I can't tell if she is trying to urinate or what but the liquid does not smell like anything. After observing her I noticed that she was licking it! PLEASE help, i cant figure out what is wrong with her.

Please do not delay- please call your vet and get her in to be seen- tonight if possible- trapazole can on rare occassions cause temporary kidney damage-

Any updates? If she hasn't urinated, this is a life-threatening emergency and she needs to be seen immediately. If she is urinating normally, she may be constipated. Talk to your vet, but you can try mixing some canned pumpkin or Benefiber into her food. Hairball medicines, like Laxatone or Petromalt, may also be helpful since they are mild laxatives. Please let us know how she is.