Hoping it’s not to late

I have been married for over 20 years. I was diagnosed almost two years ago and just started taking medication a little over a month ago. My wife had been telling/asking me to get help for as long as I can remember. I always asked why there's nothing wrong with me. Boy was I wrong. My wife is the love of my life and the reality of what I put her through all these years is heartbreaking. I had an online affair....I checked out on our marriage for awhile I was never home and left her to take care of our two young children and the household. Then she got pregnant with our third child. I said some pretty mean things to her that I am to ashamed to say here. over the years we would have good times and bad where she would ask me to move out I would dismiss her and be surprised that she asked me that. I thought all along that we were going in the right direction. I could have a list a mile long why she should have left me but she never did. I thought it was because she loved me and we were continuing to work on us. Of course I wasn't doing anything to correct my behavior.  I would snap at her, I would grope her in public, there are other things that I am ashamed of. We would have a great time together for months at a time then have a few months where it wasn't good. And we still made it. 

My wife has been in therapy a long time now and I thought it had alot to do with her childhood but also my online affair. I didn't realize the rest of it until recently. Now that I am on medication I have much clearer head and I hear everything she tells me now instead of just being there. What an eye opener for me. See I never realized the stuff I was doing to her that I mentioned already was disrespecting her and humiliating her.Of course through the years she would tell me to stop doing these things and I would laugh it off or dismiss her, I thought i was showing affection. she  told me that recently and she also told me that she was scared of me because of the way I would snap at her. Knowing that she was feeling all those things is devastating to me.. I can't believe how blinded I was to reality. I really wish I could change all that but I can't. I know that. I lack empathy in a bad way....All I can do now is work on getting better. The shame I feel is I overwhelming but I deserve it. I was an asshole!!! 
I know now that I have a lot of work to do to try and fix me. Took entirely to long for me to realize reality. I know that I will be putting in the work to do it. I have a lot of work to do with my therapist. Trying to learn what techniques work best for me. I know that I love my wife. My family is everything to me. I am working on being a better man. 
I can't use adhd as an excuse. The fault is mine because I refused to get help. If I would only listened to the person that knows me best 20 years ago. Maybe I would be the man she deserves now. I still want to be. I'm pretty sure she wants that. Determined to hold my wife's hand at 80 and look her in the eyes and say we made it. That is if she will have me.  I could go on saying a ton more but that's enough for now. Like the title says Hoping it's not to late.