I have a cat who has had three UTIs so far. As a result, I feed the cat expensive food ($36 for 18 lbs) that I must buy at the vet. The first time he had a UTI, I didn't notice until he was actually excreting blood. When I figured out what was going on, I felt so guilty that I had allowed him to have so much pain!!!
I was also guilt-tripped by the vet to bring him into the office IMMEDIATELY. Since I saw blood, there was the possability that he had a stone. Apparently, the urethra in male cats narrows toward the opening, so stones can quite easily get stuck in the tract. If this happens, the cat will die in 24 hours due to the urine and toxins backing up. With female cats, the urethra is the same width throughout so this is less likely to happen.
As far as treatment, the only thing I know of to actually treat a UTI is an antibiotic. This in and of itself should not be very expensive since you can get generic brands. However, you do need a prescription, so would probably have to see the vet. At my vet, the visit and the medicine would probably cost me about $60.
I have read a lot about preventing UTIs in cats. There is much disagreement, but the consensus seems to be that future infection can be prevented with the appropriate diet. The disagreements come over what that diet should be. I will say that at times when I have not had much money, I have purchased the Urinary Tract Health formula of the Walmart brand cat food. It took about 6 months on that food for my cat to develop another UTI. When I purchase the food from the vet, I NEVER have a problem -- going on two years now since the last infection.
My cat actually start squatting outside of the box when he has a UTI. He seems to avoid the box and will squat and strain and have nothing come out. And he will do this A LOT. This is how I recognize that he has an infection. I'm sure different cats will exhibit different behaviors, but if your cat seems to be trying to go frequently, but is not actually peeing, I'd say it is likely she has a UTI. If she is actually going each time she gets in the box, I'm not sure that is the same problem, although there might be something else wrong.
The first time my cat had a UTI, I learned that UTIs seem to be triggered easily in cats. When a cat gets stressed, they will develop a UTI. The first time my cat had one, it was 5 months after my XH left, I had been on vacation for a week and left the cats in someone else's care (although still in my own apartment), and the weather had been very strange with odd thunderstorms, etc. According to the vet, any one of those events could have been sufficient to cause the cat to get a UTI. After the second UTI, the vet suggested that if he got a third infection, I should consider putting him on Prozac for his nerves.
I hope everything works out okay for your kitty!