Commitment vs. Impulses

What do you do when your ADHD husband outright indicates that he doesn’t know if commitment to you and your marriage outweighs his curiosity for being with other women?  I am at a loss.  I don’t even recognize the man I married anymore.  He got a taste of this fix for other women with an affair and immediately regretted it when I stated my boundaries and left him.  I decided to put my heart back on the line again, against my wishes of not wanting to be this shattered ever again, but he outlined with such clarity his regrets saying he would never do anything to hurt me ever again.  He made a convincing case of never being more sure of anything in his entire life.  He promised to spend a lifetime making this up to me ensuring I know that “we are worth it” and “I am the most important thing in his life” everyday.  However, that taste of an affair wasn’t good enough for him.  He is back in the rut searching for something more exciting/new/intriguing for the time being…negating all these years of compatibility, growth, excitement, and love we have shared. 

He started taking Wellbutrin about a week ago, which I am hoping is a step toward “working on himself”.  His diagnosis of ADHD, depression, physical issues, and discussions of childhood trauma, impulses, and addictions in therapy have stirred something up in him to make him completely shut down and give up on us.  He says to compliment me or initiate anything kind for me is “uncomfortable”…I am so hurt that something that was once so easy and automatic is so difficult for him now.  I can see the discomfort, but is it more uncomfortable than the thick fog hanging over our relationship right now that I did nothing to cause and now I'm being punished for? 

I feel like I should move on, but at the same time it doesn’t feel right because this person doesn’t even feel like him.  If it is him, he did a great job of hiding it for 16 years.  We honestly do still have a pretty close to perfect marriage and relationship when he isn’t in this funk.  There are sparks of hope, but then moments of despair when he loses sight of us again.  Is there ever getting over choosing impulse and infatuation over what's real?  He has completely sabotaged something really good for no reason at all, except to fulfill whatever he’s going through right now. I wish he would've held on to that clarity and worked on making things right with us, instead of just giving in because of the hole he dug or the new interest he is seeking in his life currently.  Has anyone made it through this in their marriage?