needing some advice

My husband cheated and lied and were separated. I told him with the emotional abuse on his part and cheating that he needed to get some therapy and work on him if we ever even wanted to consider getting back together. ( I am also in therapy to work on me and have been regularly for a year)
Well he went to his moms and has been saying he will go to therapy for months and isn't. Isn't showing any signs of making any attempt to. So I feel like I'm backed into a corner and have no choice but to move on if he won't make an initiative to help himself. 
Every time he drops the kids off he makes comments about how he wants sex or "can we be special friends". Well, no......he says he's filing for a divorce. And I feel like he's just fine. 
My dad has an employee that's been around for years and we've always got along. I was out with friends a few weeks ago and was drinking and messaged him. I said some things I shouldn't have and I feel bad. I feel like I cheated. I can't stop thinking about him though and I don't want to anymore. These feelings are driving me insane! I just need some advice if anyone has any. I don't want these thoughts hindering what's going on with my husband but he says one thing and does NOTHING to change. We've been separated for awhile now :(