insecurity

I had dated this guy for a few years and we broke up a few months ago. In the beginning of our relationship, he would always talk about jerking off to all these videos and would even show me them. He would show me the magazines (playboys) he had and all that. One night he facetimed me while he was watching porn and told me to time how fast he could get off, no joke. I was never one to care about porn until all that happened, and I felt so insecure to the point that I wanted to end the relationship only 5 months in. I told him that he was making me feel that I wasnt enough and that I had to compete with his hand since it started negatively affecting our sex life. It stopped after that, but now that weve broken up I still cant shake the insecure feeling. Iv been talking to someone new and that insecurity is coming back. What should I do?