Ashley, I am sorry you are having a tough time. I am a 33/m and deal with depression on occasion too, more though as my PFTs drop. It is tough to see and accept the process when you are knee deep in it. The first thing to ask yourself is what are you depressed about? Obviously CF is a huge factor but what is making things worse? Are you going through a CF exacerbation? Work? Money? Romance? Apathy? Once you can better understand the source (beyond the CF) maybe you can seek more specific support as a remedy. If it is just the CF itself you are depressed about, that is tougher to solve. My doctors tried to put me on depression pills, which ticked me off. I was depressed about work and money and I told them no pill could bring me money or employ me, and walking through life sedated wasn’t going to help. I think a clear mind helps me solve my problems and better manage the question of my existence. I think not fighting the depression sometimes helps. That is, if you have to feel sad some days feel sad. Get it out of your system! Have your sad party, or as my departed psychologist use to say "Have your pity party, and then get on with life!" Tough words sometimes, but it helped me on occasion. I know that when my wife won't let me feel sad that just makes the depression worse, cause it is then coupled with anger from not being able to exploit my entitled feelings of doubt or fear.
You may hear this a lot, perhaps not. But, the world offers a bounty of wonderful experiences. Some of these experiences require a healthy body; other experiences only require the willingness to simply be. It doesn't matter if you are 20 years of age, 33, or 60, or even 90. Each moment has the potential to be not only worth while, but glorious. The work of it all is that you must try; you must participate at some level to fill that moment, each moment with something better. For me I hate defeat. I am not going to let my CF win, and by winning I mean take the joy of life from me.
I don't hate my CF, at least not all together. It has given me amazing eyes through which to see the world. The emotional colors that exist in my perceivable spectrum as a result of my CF are so rich and dynamic. This is a gift, and I feel I must use it while I have it. And if I am lucky I will work to share my gift with others.
Hope isn't always easy to come by. I am not sure if I have given you even a fraction of hope that you can survive and triumph over this depression. But my thoughts and prayers are with you. Be strong. Best of luck.