QS: You are emotional and over-thinking, it is perfectly understandable. Vent - share your feelings - it's good for you. Just don't act on them, for heaven's sake.
If it helps, I will share a little about my first marriage. I've posted about it other places but don't know if you've read any of those. H#1 (who I was with about 7 years total) had a PA. When I found out about it, I moved out, that very night.
There was a lot of back and forth (wish I'd known more about exposing and dealing with A's back then!) but in the end, I played hardball. It ended up that I was the one that was done - and he was begging me to give him another chance. I couldn't do it. (We had no kids and I was ready to move on. We did not want the same kind of lifestyle...)
Now: my X was one that was very prone to fits of anger during the confrontations, ESPECIALLY when I stood up for myself and showed self respect and held his feet to the fire! I was the type - as you are right now - that worried if I had gone to far, after the fact. I worried that he would run right into the arms of the OW or someone else. However, I did not give in. I cried a lot - prayed a lot - spent a lot of sleepless nights - but I did not give in to that fear. When he was reasonable, I would respond with loving toughness...but I did not back down on my stance of self respect. One day, I got a huge confirmation that I had done the right thing - months after all the turmoil. He wrote me a letter telling me that I was right - that I was the strong one, not him. That his anger was his trying to get me to fall back in line with letting him have his way in the whole situation - to play both sides of the fence. He was sorry. He said and did some awful things, btw: at my apartment, at my job, with my family... He even accused ME of cheating on HIM!
Anyway, the point is - I heard much worse from him than you are hearing right now yet in the end, HE wanted to reconcile and I did not - even after the divorce was official! His actions, as well as that letter, confirmed that all his words and actions were just a smokescreen. I was so glad I had not given in when I wanted to run apologize or beg or plead. The only time for any of that is when the WAS is fully ready to commit to the M and do WHATEVER it takes.
Read DB or DR: what your W is saying is classic: "If only you hadn't done THIS... Now you've ruined it..."
I know the process hurts. It isn't for cowards or else everyone would do it and a lot of crap would end! Take heart that you have done the right thing - the ONLY thing that can save your marriage.
