It makes me sad that you are in this situation. When I was younger I would have told you to stay in the marriage at all costs (except physical abuse.) I like to think I'm wiser now...but still honor the marriage contract.

It appears that this was flawed from the beginning, and I think you have inasmuch said that. Couples counseling would be my first suggestion. If both of you are not into making this work, beginning now, then I would say, get out while you can, with as little invested as possible.. and chalk it up as a mistake you won't make again. It does little to stay in this without doing something different, imo.