It is the worst feeling there is and I am so sorry you are going through this.
One of the reasons my wife gave originally was my working too much. Some weeks 80 plus hours.
But nothing, absolutly nothing you have done has made him do this to you.
You are not to blame for his affair. That was a choice he made.
You can take some responsibility if you must for where the marriage was before the affair but that is entirely separate from his choices.
My wife went through multiple stages after I found out. There was calmness and almost relief to start with along with she was not only to blame for it.
Then she became almost its done its out why are you still upset. I could see she didnt mean this but it was almost like let's sweep it under the rug and it will disappear.
There was anger from her following that with a lot of blame shifting. I knew her well enough to know she wasn't really angry at me. And I refused to pander to it and let her strop while I calmly got on with whatever it was I was doing.
Then there was a moment of clarity my daughter witnessed. So many emotions running through her our daughter thought she was going insane.
She then took full responsibility and accepted all the blame.
We went from near certain divorce to working on us together.
I went through multiple stages too. Within a couple of days I thought right let's get back on with work, I'm dealing with this well enough to cope. Someone I work with who I'd told didnt believe me that id be ok. They were right. The next week it hit hard and I broke.
While we are working on it its still not ok. I'm not ok and I doubt you will be for quite some time.
Counselling helps. So does talking to the right friends, ones who will not tell you what to do but will be there to support you in your decisions.
Have you talked about the future? Divorce or work on it or somewhere in-between?
I was dead set on cheating is an automatic end. No second chances. But then I found in the face of it that wasn't how I actually felt.
Also, remember to look after yourself and remember to eat and drink plenty.
You didn't do this and you have nothing to feel guilty about.
One day at a time. Stay strong but alow yourself to break when you need to.