thinking about leaving bf because he doesn’t satisfy sexual needs

Hi, I’m a 21F and my boyfriend is a 20M. I’ll call him Justin. Justin and I started dating almost 8 months ago. I was the first person he had sex with, made out with, dated and even had a relationship with. The relationship has its ups and downs like any other normal relationship. I had to “teach” him a lot sexually because he had no experience. For the first couple of months my sexual needs weren’t met but I didn’t really care because I understood he was new to this so I gave him grace. As time kept going though it just felt like sex was becoming a chore for me. He doesn’t do forepl@y or anything really centered around me. He never really improved in bed even after countless times of me telling him what I liked or didn’t like. He was just really terrible at everything. I voiced my concerns to him and he kept turning it on me in any way he could to make it seem like it was my fault. Most of the time we had sex he would just lay on his back. Most of the time during sex we wouldn’t kiss or makeout or anything. I constantly voiced my concerns and everytime he still leaves me disappointed. It is now going on the 8th month of dating and he hasn’t made me orgasm one time but I have made him orgasm all the time. Even when he does try, he is terrible at sex. His penis is average size (6 inches) and he’s not the best at using it either. I’m starting to get really sexually frustrated and starting to resent him to the point I been thinking about cheating but I haven’t acted on it yet. I told him my sexual needs matter too but even when he used to try to please me, the sex was just always terrible. The forepl@y is terrible, the d!ck game is trash… everything is terrible. It’s to the point where sometimes I start to cry after sexual activity and all he can do is console me by saying he’s sorry. He hasn’t went down on me once in the past 8 months and whenever he “tried” he would make an excuse up. I know it’s not because of a v@gina smell. I even asked him if I smelled and he said “no.” No matter how many times we try to solve this issue of our bad sex life, nothing works.