Maybe it's not easy to hear but my shrink told me that when I quit it's not going to make anything any better, especially in the short run. He said my problems might even seem bigger since I won't have a way to drown them out.
That helped me set my expectations. So I'm going in thinking, "this change is going to suck" and then anything better than suck is a pleasant surprise.
Anyway like AnonSara said, at least you can see your problems more clearly and don't have to hide them or from them.