A never ending cycle of infidelity, is it ADD/ADHD?


This might get long so I apologize. Trying to keep it short and give the facts but there's tons. 

My DH and I have been married just over 4 years, together for almost 6 with a little break before marriage. Everything seemed great at first when we dated, he was so intensely passionate and loving. Very attentive and caring.... till a year and a half in, after never having a single fight he cheated on me and left me high and dry. 2 months later he said he realized it was a mistake and came back and we got married 5 months later. We each have children from our prior marriages and now have a 3 year old together. When our son was 5 months old he began the emotional affair again with the same woman he had cheated on me with before and continued it for almost 2 years with me knowing the whole time, only this time he didn't leave but he kept blaming it on little things that I did that bothered him horribly. I put a lot of effort into not doing those things anymore and now every issue he has ever brought up to me (always after a cheating episode) I have resolved. 

I have also had issues with him going on Craigslist and emailing with people about disgusting sex acts, often men, but as far as I know he doesn't act on them (except once that I know of before we were married). I have found evidence of this all through his first marriage and apparently even within the first 2 months of us dating. It's extremely hurtful and he knows it is but he still does it. Any time I go out of town for business or family (things are great beforehand) or we get into a fight and he decides to go stay in a motel this is what he does. Sometimes he does it sitting right on the couch with me when absolutely nothing is going on. We have sex regularly so I know it's not a lack of attention there. And every time he comes back swearing he does it because he's so unhappy with me, he doesn't care about me or how I feel, and that he feels I force him to stay. Then when things calm down we have fun and times are good and then he does it again with seemingly no trigger. It's happened at least 40-50 times now where he has these episodes. 

When things are good, they are good. And sometimes we can go a month or 2 without these issues. But they always happen again. I know he was diagnosed at 14 with ADD. I am loyal, honest, caring, ambitious, faithful, I don't do drugs, I try to communicate which is always met with anger. I work hard to meet his needs that he says he has but he says I'm needy in wanting him to just text me during the day to say hi which takes 30 seconds, yet he could spend hours chatting with someone else.  He seems very lax in responsibility with his 2 teenage daughters, never enforcing rules or consequences, yet somehow I'm a bad parent and always have something against them when I try to teach them something. But apparently everything I do with my own daughter is wrong. Everything is a double standard. 

He runs and plays the victim about how hard his life is every time he does this too. But I honestly believe what's really going on is that he is having impulses that he doesn't know how to control and he's trying to justify them by convincing himself and anyone who will listen that he's got it so hard. I have asked him why he cheats and he will say he doesn't know why once things are more calmed down but in the moment he's always blaming me saying it's because I get frustrated too easily when I lose something for example. He can't see the fact that he's been cheating long before we ever got together and also long before he ever even had a chance to see these "flaws" in me. It started even with us back when things were still new. I think he has low self esteem and is trying to get validation and then to save himself the shame, he's coming up with reasons why he has to leave me. 

If he wants to go do something, I don't complain anymore. If he says he will be back in an hour and comes back 5 hours later I don't complain at all. He usually doesn't get home until after an hour from when he gets off work, I don't call and ask where he is. I ask very little of him, but really miss the times when I actually felt secure, loved and appreciated. He says I am needy for needing those things. 

Needless to say it's all very hurtful and I don't know what else to do. He has never really taken full responsibility he always claims it's something I did to drive him to do it like the frustration I sometimes experience, never big things like sex, trust, or big marital responsibilities, I want to keep my family together, but he's so convinced that I'm his problem, he doesn't even see his actions for what they really are. He's finally said he's getting counseling but of course doesn't want to even be with me when he does it. Says he mostly needs therapy from dealing with me yet once again his biggest complaints are about how I get frustrated, and how I have tried to instill boundaries for his kids to help them (which I have detached from that 6 months ago). 

I should add he's also very financially irresponsible, has extreme communication issues (even his mother says that), is very forgetful, procrastinates, and has a history of job hopping. 

Does it sound like ADD or ADHD could be the root problem? If so, how do I get him to realize it or even look into it with counseling? How do I get him to make sure that he's focusing on the right things in counseling (himself and his habits, figuring out why, making sure he gives the full story). How do I get him to realize that will be a lot more helpful than trying to spend his time focusing on supposedly how to deal with his wife? I would like to explore marriage counseling after a few months of his own therapy, and I realize I can't control him. But there's more than just him and I at stake here and I think things could be good if he could learn about the issues within himself that cause him to feel the need to cheat, and how to control those impulses or redirect them. I'm searching for answers in the hopes maybe he will be more willing to explore them if he has direction. How can I encourage him to make sure he really digs deep into himself and accepts responsibility for his own actions? Will a therapist be able to see through it? It's so confusing when he goes from loving to hating me in a matter of minutes each time he gets caught. And the worse his transgressions the meaner he gets. 

Any ideas and insights are welcome. I want my family as well as we can be. I'm trying to stand by my husband but it's hard when he's trying so hard to blame me for his issues that existed long before me. If you made it here, thanks for reading and please offer any suggestions or advice.