I don't know if he's sincere but I can tell you that his words alone have no value. He has lied to you so much, for so long, and he's very good at it. The only way for you to assess his honesty and remorse is through observing consistent action over time.
convincing himself that he was a good father and husband while treating his betrayals as just a "side part" of his life. He now sees how selfish and destructive that thinking was.
Many cheaters are great providers, excellent homemakers, and/or very active and involved parents, so it's very easy for them to lie to themselves about how their affairs were just harmless diversions.
But in your husband's case, he was underperforming at work and at home-- you have been shouldering the financial, housekeeping, and child care burdens for your family, while he spent considerable time pursuing sex and romance with others.
His betrayals weren't a "side part" of his life; your marriage and children were.
So while it's possible that he understands how much he harmed you and his children with his cheating, he's still deluding himself about the extent of the damage he's caused-not just with his cheating, but with his neglect. He's trying to minimize the fact that cheating and deception have been central to his life.
He admitted that all this time he thought he was in control, but now he sees it was actually the opposite—his selfishness was controlling him.
This is dissociative language that it's intended to distance himself from his actions. Instead of saying "I am a selfish person who does selfish things" he describes "his selfishness" as if it's this nebulous, external entity that was pulling him by the strings. He's trying to portray himself as the victim of his own vile acts, rather than the perpetrator. He is not the victim; you and your children are.
While it's possible that your husband might have some of compulsive disorder, he certainly had a strong enough handle on himself that he was able to successfully lie and hide his behaviors from you for years. He will never admit it, but I'm sure he benefitted from the fact that you were so preoccupied with work and caring for your children that you might've been too tired and distracted to notice what he was doing.
He became someone he himself can barely face in the mirror.
He knew he was lying. He knew his true face all along. What he's having trouble coping with is that you see it now, too.
edit;add
My question is do all serial cheating husbands say the same things as the weight of their actions settles in? Are these usually temporary feelings?
To reiterate what I said in an earlier post, I think the question you should be asking yourself is not whether he can change or whether his remorse is real (or whether all serial cheaters do xyz), but to seriously look at the relationship as whole and decide whether it's acceptable or not.
I think that, if you're being honest with yourself, you will realize that your marriage has survived thus far because you were willing to make excuses and compensate for his shortcomings and selfish behavior.
"Not cheating" is the bare minimum you need to reconcile. He needs to completely transform his personality, his character, and his outlook on life. Your relationship dynamics need to completely change-- and that starts with you refusing to carry the load for him.
I think that part is going to be the most challenging for you because you see yourself as a "fixer" and don't want to "give up" on someone you love. You've probably also neglected your own self care and personal interests because you couldn't rely on your husband to pick up the slack for you whenever you needed time for yourself.
Lastly, you need to ask yourself how many years of your life you're willing to sink into this process before you even know if the outcome you're hoping for is even possible.
[This message edited by BluerThanBlue at 3:07 PM, Wednesday, May 28th]