How to live with this mistake?

Basically, I've let everyone down. I got married just because everyone told me not too. don't plan on getting a divorce so don't even say that. ( I think marriage is for life so I just need to deal with it) I miss my home so much nut my husband wont moe off the coast. I feel like I've amounted to nothing. Sometimes I wish that i would get in to some kind of freak accident so I could just disappear. Or maybe just running away and living as a female hermit (no I'm not kidding) I just feel like my whole life has been nothing but one big let down and i'm only 20. what do i do?