Too skinny for sex?

I recently went from 130 lbs to 115 lbs by changing my diet to get "healthier". Last night after having sex with my partner, he said my pelvic bone was hurting him so he didn't enjoy it. He also hates that my ribs, hip bones and spine shows. I'm 5'3 so idk why I look bony since I know other women are smaller than me but can pull it off. Has anyone ever GAINED weight to make sex more comfortable?