First, have they genotyped you? How did they decide that you have CF?
The decision to get a lung tranplant is a major one. It is a decision that you must make with your doctors. You have to decide if you can handle the post-op meds and make sure that you have an adequate support system, such as parents, friends, or a significant other. We are starting to consider this as an option and our doctor said that I will have to take about 6 weeks off from work to take care of my husband after the surgery.
If you keep going in and out of the hospital it sound like they aren't keeping you in long enough in the first place. When my husband goes in, he is there for at least 10 days and up to three weeks. They let him go when his lung function tests indicate that he is well enough to leave. Also, many of the problems with CF are the result of a bacterial infection. Make sure that your doctors have cultured you sputum and determined which antibiotics work. Over time they will become resistant to antibiotics. You also need to be on anti-inflammatory medication and something to break up the junk in your lungs.
Regarding the vest, my hubby says that it doesn't really work and that it just makes him sick to his stomach. There are different vests on the market and I'm sure there are some that fit better. The other issue is that he has a port, so the vest rubs up against it.
Anyway, I hope that helps.