Yeah, I agree that you should get to a vet sooner. Xrays should be able to show what the problem is. A luxating patella is pretty common, especially in smaller dogs. Most of the time, surgery is not required. However, if surgery is required, you should do your research. I've known dogs who have gotten the surgery for LP and ended up slightly worse.
My Vinnie does have a LP, but it is minor and my vet said that it was not severe enough to do anything about. My vet did recommend Keeping Vinnie's weight down, exercising him regularly, giving him glucosamine (to prevent inflamation and joint damage), and doing some massaging exercises on the inside of his leg (to loosen up the tight ligament). I will say that I have more or less following this regimen for the entire 6-7 years I've had Vinnie and he has not had a single issue with his LP. Every once in a blue moon (maybe once or twice a year) his patella will luxate, but it only slows him down for a minute and then he's fine.
You mention that you are in college and that surgery is out of the question. You need to consider that having a dog is costly, and a serious responsibility. I will not go so far to say that you should not have a dog, but you need to be prepared. You should stash away whatever money you can for a rainy day fund, a fund that you can use for emergency vet treatment. Most of us who have dogs WILL require some emergency vet care at some time. And it is expensive. Look into pet insurance.
When I adopted Vinnie, I was in grad school and money was tight. However, I was very careful to have money put aside, and I dipped into that money on more than one occasion for him. Just please consider!!
__________________ Andrea,
Mom to Vinnie  , Alex  , and Guru |