I wish you didn't have all those confusing feelings and difficulty, too. But it seems to me that getting married isn't going to help ANY of that, and ultimately it will just keep you trapped--way more than you are now.
It seems to me that the safest course is to cancel the wedding--at least for now. You don't have to leave him if you aren't ready to do that, but why tighten the knot harder than it already is?