Bad sex....What to do???

So I’ve been with my bf for a year now and I’m not sexually attracted to him. We’ve had sex a few times and I’m never satisfied. We’ve talked about it and made adjustments, but the last time was in February and it wasn’t good. He’s not as big as my last partner but I think you need to learn how to work it. However my sex drive is there I’m just sexually frustrated because I know he can’t fulfill it.... I’m not sure what to do