Having husband troubles

Ok so this is a very long story I will shorten it up the best I can, me and my hubby have been married four years but together ten we have two children and I love him very much. When we were younger he had cheated on me numerous times while pregnant with our first child we broke up for a while he ended up going to prison and we got back together did a little marriage counceling while he was on parol and things seemed to be great the first two years of our marriage, but once he got released from parole it was like he turned into another person, drinking a lot and flirting with other women in front of me even telling them what a nice a** they have. I have also caught him looking at porn and we have been fighting a lot he has spent money on porn sites behind my back as well as poker games I'm talking hundreds all though he has not cheated since we have been married all those old feelings are coming back and I feel like it's a matter of time before he does and he refuses to take anymore counseling with me but isn't doing anything to help me feel secure again in our relationship, he says he got drunk and made a few mistakes and that they won't happen again that it's my insecurities causing the problems in our marriage, what do I do?