Why does life seem so bleak and helpless to me...?? Help?

I'm 18 years old guy and I should be feeling the contrary, as with most of my friends. I believe one big factor to this is the fact that while most of my friends are going to universities straight after high school, while I am not because I messed up in high school (horrible start, decent finish) due to personal and health issues. So I don't know what to in life now...? And I'm constantly feeling depressed and ashamed, to the extent where I have severe insomnia and nauseating pains in my head and cases of delirium. I also feel a little F*cked in the head, cuz my mind wanders so much and I can barely focus. I'm the brink of a nervous breakdown, and possible a mental one too. Help me out please? (don't care if ur christian, jew, atheist i just need counsel)