Worried - "Husband had an affair"

Husband had an affair. He came out and told me. First time he was friends with her for a few months then turned sexually for about 2 weeks.

It ended for about a little over a year. Then after about 13 months he started again, He said It was just sex this last time and lasted about 2 weeks?

We don't fight much! Have fun together. Like the same hobbies. Married for 11 years together for 13. Have one child.

I have a bad feeling all the time! I have forgave him but, i can't forget everything. It's so hard to build the trust back? When that person that hurt you so bad but, yet can look you in the face and say they love you and then turn around and lie!

He said he was confused and he thought that I was not Happy and I didn't love him. I know that he just said that to make himself feel better.

He said he has stopped and it makes him sick to think about it? How do I know what to do! I feel so confused?

I don't know what to believe anymore.