My boyfriend thinks he’s a letdown

Recently I lost my virginity to my boyfriend and it was a big moment for us! After the first time we did it a second and made progress at being even better. Then last night we tried a third , on the floor instead of the couch, and he kept slipping and I had to take him out a few times and reposition and he got really upset and thinks he made backwards progress and doesn’t understand that it was all on how he was positioned (cause he kept complaining how uncomfortable he was and how his positioning felt awkward) and not him being a “failure”🙄. Can someone say something that will convince him he’s fine?? He just won’t listen to me..he’s very sensitive and thinks if it’s not easy then he’s not a man.....💆🏽‍♀️🤦🏽‍♀️