Wow, Jen, I am really sorry to hear that you are in the dumps. You sound like such a really cool girl, helping all and such. Treating all people with total respect, trust and friendship.
Many times in our lives (older folks insert all the examples you want) we go through trials, our character is tested, then re-tested. Then it is spit out like a used piece of gum. It is how you overcome these bullshit things and prosper, emotionally you have to put this kind of thing past you.
Medically, aside from the obvious diseases that can be avoided, Shit happens. It fucking sucks, the gene pool is a really fickle bitch. I hope beyond hope, that you are ok and the med aspect is not an issue. I know you said a "condition" but hopefully is is something curable.
So you question life, this is something that everyone of us do. We ALL do. I hope that you can find a "happy" place with your friend, friends are what makes this place habitable. If not, well, move on and meet new people. Shit that is easier said than done I know. My girl, bottom line is, be happy in where you are, what you do, and who you are. If you have all of those, this place is a cool spot. You can find happiness in it.
It may sound creepy and all, talking with a boarder. But if you feel like talking, I am here for ya. PM me and we can talk some. Hell girl, I am in Cleveland, maybe you can swing by sometime. Ask Will, my steaks are legendary!