If you focus on your kids and give them lots of love an attention they will be fine. I was married to an A and had two kids. He was very abusive and drank a lot everyday. I divorced him when my kids were 1 and 2 years old. That was 20 years ago.
My ex has never admitted to being and A and still drinks daily. My son is in treatment now for Alcohol. Part of his treatment was writing a letter to his dad. He will not send the letter, it was just to get things out. Anyway, he read me the letter and it broke my heart. It doesn't matter how old they are they do take it all in. The good part was that he told me that he had always had everything he needed in life. Even though I didn't have much money at all for years I was there for him and his sister and gave them lot's of love.
Marrying and A was stupid and having kids with him was worse. But my kids appreciate that I got them out of that situation and gave them lot's of love. It doesn't totally make up for all of the pain they suffered but I did the best I could at the time and years later it is nice to know that they realize that.
Best of Luck, DMOM