What should I do

Sorry for the long post ...

So I’ve been with my husband for 10 years and married 3. Just before the wedding I found out he cheated with his ex for the first 3 years of the relationship! It broke my heart I had no idea. They had been on holiday (he was supposed to be with the guys) we were I though totally besotted from day 1 and I had been cheated on before in my previous relationship and also suffered domestic violence which he knew so it just felt like a stab in the back. I continued with the wedding because it was so close and I was really confused. It has eaten me up for the last 3 years. I’ve been forgiving at times then at times I think what are you doing get rid of him. She is still so close to his family which makes me feel like an outcast. I have two children from the previous relationship and most of the time he is good with them but they are beginning to dislike him as he is so strict and can often be childish. He likes to make a mountain out of a molehill. We recently moved from what was my house to now our house and he’s gotten worse. I’ve asked him to go for some space so I can think and he has reluctantly left after weeks of me pleading but now I’ve found out I’m pregnant. My head is everywhere!