There is no magical spell that will dissolve a marriage contract.
If you fear for your safety please go to the police.
You need to speak to a lawyer in order to dissolve the marriage.
I suggest looking for impartial advice. Does america have a sort of citizen's advice beaureu like the UK?
USA has many places you can go for marital problems. And if you're in the USA you have the right to do what you want so i don't see how you can't. If you're afraid of him... again.. many places you can go, most common... The police department xP