How do I get over this & is this my fault? What did I do wrong, men I would like your input too.?

You are taking on way too much blame. He used you. He was able to string you along for 8 years. He kept you where he wanted you, on a leash to pull you in whenever he wanted. He was in control. He is not worthy of you. He will always be a cheater and a manipulator, but not with you anymore! He will cheat with the other girls too. Close this chapter in your life. Do not ever let him see you sad, let him see you HAPPY because you have moved on.