Where did I go wrong?

I need to share, and if anyone can tell me where I went wrong?

When we met my husband, I didn't want to be involved with him at all. I didn't like him, but for 3 months, he was very insistent. We were both not attached to other people.

So, at one point, things started to go great between us. We loved each other and we were happy. After a year and a half, we got married, and after another year a wonderful boy was born to us, who is now 4 years old.

I had (and still do) a great job, and he has his own business. When we talked about working together, he flatly refused to work with the person he lived with.

One week before our child was born, he hired a new accountant, who was divorcing at the same time. A year ago, exactly on his birthday, I found out about their relationship. I wanted to keep my family, but I didn't want her to continue working for the company. I put up with her there for another two months so she could finish her unfinished business. Naturally, I reacted quite violently at times.

He wandered for several months between me and her. I endured his beatings and his malice towards me, until one evening my father had to come and take us with my son.

The mistress even moved to another city, which drove him even crazier, and he moved out of the house, and I returned to live there with the child. He has gathered so much malice and hatred towards me. And I can't explain to myself why.

I can't figure out where I went wrong? I tried to be a good mother and especially a wife, but he was still unhappy. I overcame my feelings for him, but the pain of betrayal will always remain in me.