Help with bring flare back into sex life

Hi everyone,

Me and my bf have been dating for four months and are now living with each other but we've known each other for about 7 months and been having sex for that length of time as well.

Lately I've been feeling like we're both treating sex as if it's a chore more than something we enjoy.

Does anyone know any different kind of positions to help bring a flare back into our sex life and can you tell me your experiences with it. By the way we're 22 and 18. If age helps anything at all.

P. S. My bf loves when I ride him but I'm not very confident with doing it as I'm considered plus size and just don't think I know how to do it very well. Any tips on that as well.

Anything helps really