Sex Advice

So I lost my virginity to my boyfriend and I thought it was really nice. However, he has had experience and one day I was curious about our sex life. I told him to be honestly with me and how good I was in bed and he said "maybe a 6". So after crying my eyes out in my room, I came to you guys bc idk what to do. No I'm not a young individual who shouldn't be practicing sex. (For those who may be questioning I'm 23). I just feel so insecure and unbeautiful around him during sex time. I just don't know

what to do... what can I do to get better with sex ?