One year cheating anniversary...

It has been a year since I discovered my husband cheated on me. It was a horrible day. I looked in his trunk, in the area that holds the spare tire, and there was a phone  he had hiding. In the phone there were explicit texts and pictures. I was so hurt. This is understandable. But what I can't understand is why I'm still so hurt. I'm not going off on him anymore. But I do still question him about it and wonder if he is still cheating. I'm staying because I love him and I want our marriage to work. But I have also been wondering if I should just end our marriage because I can't let go of what happened and just trust him. People have told me that since I have forgiven him then just let go of what he did completely. I'm confused by this because I never said that I forgave him. He has been wonderful after he cheated but I still can't just get over this. Please help