Positions for skinny bony women

I’ve lost a lot of weight and pretty much lost my butt and am too skinny now. My husband has brought it to my attention that sex hurts him a little now and doesn’t feel very pleasant because I’m so bony. I’m working on gaining muscle and looking into possibly some plastic surgery but in the meantime can anyone recommend some positions for us skinny girls? He says his pelvis bone hits my butt bones which doesn’t feel pleasant. If I do cowgirl it’s worse because my butt is constantly clashing into his pelvis. This is honestly taking a toll on our relationship and we both miss each other intimately. Any tips ?