Trust issues sex related

My husband and I have a son together and we started pretty early I was 16 when I got pregnant. He cheated on me when I was 6 weeks. I threatened leaving and he somehow convinced me otherwise since that day he has struggled with porn and hacking off to pictures of my friends. The worst thing is I fought him doing this right after we had sex. I don’t understand why. I struggle with self value as it is and my look after having a baby and it makes me feel even worse. I have issues with anorexia and other eating disorders he tells me to stop and that I look good but then he goes and does that. What do I do?