Marital problems

I am in desperate need of good advice. I have downloaded your app and been listening to your talks. I have been having marriage issues for a while now and my husband and I almost got separated about a month ago he moved out the house and after some time came back. We then left for umrah about 3 weeks later only to come back from umrah to find out he has been cheating on me for some time now. According to the girl it's been 2 years according to him it's from late last year his not sure exactly when but she has known him for 2 years now. I am hurting really badly I don't know what to do. I have forgiven him for it but it's not the 1st time I have found out about him doing this. We are married for 5 years now. How do I go about dealing with this issue? I feel I should let him go and move on as he causes me a lot of heart ache not only this buy many other things.