How do I make my bf more confident?


So little story time, TLDR at the end for y'all lazy asses.

My boyfriend (19) and I (20) have been together for 10 months now but we just very recently made love for the first time (last Wednesday). The reason why we hadn't done it before was mainly because my bf has a very low self-esteem when it comes to sex and he thinks he isn't good at it. He's only had one girlfriend before me. We did oral and handjobs before that and each time he would ask me if it was good. Same thing happened when we made love, he asked me if it was okay, but didn't seem to believe me when I said it was. I don't know why he's so insecure but I would like to make him feel more confident. Do you guys have any tips?

TLDR: My bf thinks he's bad at sex and I want to make him feel more confident.