I don't have much to add....... only I could say some things verbatim that you did.

I KNEW my ex was not good. He has cheated on every girlfriend he has ever had. He has treated everyone like trash. I knew exactly what I was getting into and I got into it anyway being I was going through the most awful time of my life and I grabbed onto anything I can. I continuously live after all of these years of the guilt of knowingly getting into this. I chose to marry him, overlook everything, have a kid with him and I feel guilty all the time.

And I've told others this before, but I live with so much shame in it..... my exH was my friends boyfriend. We were 19, she moved away, he pursued me, my life was falling apart in every way imaginable and I took the bait. That friend was also an OW with his GF before!! Good news is.... we are extremely good friends to this day. She fully forgives me and I am remorseful and ashamed to this day.

I mention that because 1) It highlights how I knew what I was getting into also, 2) I feel like my whole life is karma for what I did.

And my ex is still the same guy only with a different wife too. I think they are their own version of happy. What they have work for them, but it certainly didn't work for us. I thought if I was a certain way, or if I did something different, he wouldn't have looked outside. Boy was I wrong.