Relationship Advice

Im 16 and he’s 18. We’ve been together a year and a half. My problem is when him and I first met I thought we were loyal to each other and I was 15 so young and dumb. I’ve grown and learned a lot since then. Anyways he told me tonight when we were talking about our “anniversary date” that it’s not rlly our real anniversary date cz when we first started seeing each other he was still talking to other girls cz he didn’t think we were that serious. Even tho this was a long time ago I feel hurt by it. Cz right from the start I rlly liked him and he was my first real bf. In the beginning tho he was horrible. He would take me to a parking lot and I’d give him a bj and then he’d take me home. He used me. This went on for a few months till I had enough of it and over time things changed. We went out more, spent a lot of time together, Met my parents, I went to his prom. Even tho everything is good now and we love each other I still feel disgusted w myself for staying w him after he treated me like that in the beginning. Tonight when we talked abt it it brought up bad memories. Now I just feel upset. What do I do? Should I just let it go or end the relationship?