I also think you should seek some counseling before making ANY major decisions about stopping treatment for your cf. Without knowing any specifics about your present health status with cf, i just feel that at 19 you are so young. When i was a teen i made rash decisions and big mistakes.
Luckily ( by the Grace of God) i made it thru and survived my " troubled times".
Once you are treated for depression, you may see things in a different light. Depression is a serious situation. I have been there and when you are there, nothing seems important anymore, not even living. Once you find a way out of it you see things so much differently. If you are treated for depression and still find you truely want to stop treatment because you have just had enough, then at least you would be making that decision based on your true feelings and not just depression. I know this is hard on you and I will say a prayer for you <img src="i/expressions/rose.gif" border="0">