He’s a great guy, but horrible at sex

I (20f) have been with my boyfriend (24) for three months and he’s a great guy. He’s super funny and we care a lot of common interests, he’s like my best friend but he’s horrible at sex. He can’t make out, waaay too much tongue. He can’t hold positions for long, or keep a good, intense rhythym. I don’t understand because he says he’s been with a ton of girls. I expressed my concern and he’s tried to improve, but then it’s some how worse when he’s trying more. Should I leave him or give him an opportunity to get better? I’m really unsatisfied and I don’t know what to do.