I'm very worried....

I had posted in cat behavior about my tabby-siamese Lake that has been using the bathroom in our things. I should have verified what I meant. She is urinating in the vents, bathroom sink, bathtub, and clothes we may have in the floor. She does not poop in the floor, but uses the litter pan. When she urinates, it is only a little bit. She has been doing this for awhile, and I made her an appointment with our vet soon. She is not fixed yet, (strictly inside) though and that is the main purpose of her vet visit. I am worried she may have something other than a urinary tract infection. She seems like she is constantly cold and lays on the floor vents and sleeps. She is almost 2, and if you didn't read the other post, she was only 2 weeks old when we got her. Her mother had been killed by a car and a local vet gave away the babies. We bottle fed her, and she grew up really playful and healthy but now she seems different. She cries awful when you pick her up sometimes like she's in pain, and she is not gaining weight. (Not losing either though). My boyfriend is so in love with this cat, and if anything happens to her it is going to crush him. If any of you guys have experienced anything like this, please share with me. I can use any help, as I'm thinking the worst.