I can't get over that my SO looked at porn

Rachel • Expecting our rainbow baby in january
Sounds minor I know. I was abused for years and have a had time with this topic because of it. So in order to help you need to accept that my view is porn is cheating. You don't have to feel the same. I believe when my husband said he wanted to marry me it meant I will always be enough and he doesn't need to look at another woman to become aroused. 
When we first started dating I told him my views. I said if you like looking at it this isn't the relationship for you. I view it as cheating and will leave you. 
So recently I found a video in his phone of a woman striping. Long story short I caught him after many years. Him and I are hardly ever intimate and he would wait until I was gone or asleep to look at porn. Or he would look at it and then come and sleep with me. His excuse was I told hi. I was in the mood and he wasn't. If he can't get aroused by me then I don't want sex. 
I have struggled for months to forgive him and I am really having a hard time moving passed this issue