how do you...?

How do you get back to loving your husband the same after you found out he tried to cheat on you before your wedding and was talking with the same girl about a year later? Nothing happened but I just feel so betrayed that I hate seeing other happy couples and just cringe at seeing them. I hate that they are so happy and I'm not. It's gotten so bad that its effecting our sex life. I just cannot seem to let it go. It's been about 9 months since and I just cannot seem to let it go! I need some advice with some techniques to get past my hurt! Help!