Help im going to kill myself?

I been down lately and my head feels like its about to explode from so many emotions i am going through. I am a high school graduate, age 18. I just recently lost my job and I have no car. I live under my moms roof and I am pressured to move out and do something with my life. In school I didn't pay attention because I was depressed and anti social, so I felt lucky to go home ever day. I slept in most of my cles and somehow ped high school. I cant even p stupid military test.....! I got a 15!! I am truly stupid. I feel as though I messed my life up and I am screwed. I just want to end it. I don't know what I want in life or what my careers should be. I am in a paradox for some time now! theres so much I want to do in my life that I know I cant do. I cant concentrate for a minute. I love astronomy they don't need me and plus I suck at math. My head hurts so bad! Help me please! I have it so good but screwed it up! People are struggling while I am sleeping 10 hours a day and I cant make up my mind!!!