I’m bad at sex...

So I am really bad at sex. I find it pretty awkward. Most of the time I don’t even have a sex drive ( my poor bf gets sex like once every 4 months) which I think is because of my birth control. Penetration always hurts. A LOT. ( the bf is a big guy down there) The angle of his penis is kinda difficult to maneuver, so it takes like 5-7 minutes of us poking around down there just to even get him inside of me, EVERY single time, which means I get all bruised and sore down there before the sex ever begins. Plus I have this movement disorder/ muscle weakness problem so I can’t support myself for long. BF on top is the easiest and I enjoy it after that initial pain of penetration. But he’s bored with it and tired of working so hard, lol ( 3 years of him doing all the work, lol) I have enjoyed being on top in the past, but once again his penis angle is hardly compatible with my vagina,( basically it is angled facing him when erect) so me on top only works if he is sitting straight up in a chair or on the couch and not slouching. But those are the only positions that have worked. He wants doggy. That just sounds like a lot of poking and bruising and failed attempts, and the longer it takes for him to get inside, the faster I lose interest and dry up! Basically, any advice or suggestions are welcomed pertaining to improving sex drive, positions, less painful penetration, staying in the mood. Or perhaps I’m just a lost cause, lol. 🤷🏾‍♀️I feel bad for him. He’s been a very patient guy with all of my medical problems and low libido, and boring sex...