Why Shouldn't I Give Up?

I have bipolar disorder and have incredibly low depressive episodes and extremely high manic episodes. I suffer from insomnia and chronic depression to go along with that. I have tried to kill myself a few times and I have suicidal thoughts almost daily, even when I am manic and feeling on top of the world. I am also bisexual and have a lot of problems with my sexuality, accepting myself, and my personal identity. I also have problems with drugs. Despite all of this I somehow managed to get through it and I got my degree. However, my life's dream was always to join the military and then become a federal agent. Yes, you can say I should have done more research on my life's dream but I guess I am just a moron. Anyway I recently found out that you can not join the military or any government agency if you have been diagnosed with bipolar disorder. So the whole point of my entire 20 odd years has crumbled. I feel like I have no power or control over my own life. My illness has taken everything away from me, including my dream, the one thing I thought it couldn't touch. I am now completely lost and I don't believe I can move on, nor do I want. I want to kill myself very badly and am probably going to go on a crazed drug binge very soon. As I stated above I have always had trouble with drugs and I have dabbled but I was able to curb it for the most part because I wanted to join the military. Now I am furious that all of the pain I went through was for nothing and I am just going to give up.

My question is what can I do to stop this? My life has always been extremely hard, it is a roller coaster with incredibly high peaks and incredibly low valleys. But I don't think I can overcome this. Heck, I don't even think I should. My whole mission is gone and I am supposed to accept that? And before you ask, no there is nothing else I am interested in, there is no other career I have ever wanted to do besides this. I was given far more weaknesses and negatives in this world than I was strengths. I have no special skill, ability, or talent. I am not extremely intelligent nor am I exceptional at any one thing. The only thing I ever had was a fierce tenacity and the will to persevere and to serve, to help people. Now I have been told I am too damaged to lay my life down for my country, for justice. If I am too damaged for that then I am too damaged for life itself.