You're right to do what your heart says you need to do. I'm sorry that you're hurting, but at least now you're in a place where you can take care of yourself.
He may be capable of working through his issues, but it's not your responsibility to hold his hand while he does it. You have to look out for numero uno. Your heart is too important to put on the line if he's not even willing to try to be honest.
As cliché as it sounds, it does get better with time.
Gralson: my husband. Auto: my girlfriend.
Zoffee: Auto's husband. Cue: Zoffee's boyfriend. Bookie: Cue's wife.
"A real relationship doesn't properly begin until the NRE burns away. That's when you have to start dealing with this person as an all-around human being, replete with irritating little habits. When disillusion sets in, love can begin."