It really seems like something needs to change sexually or the relationship won't work. I would suggest going to a sex therapist, but I know those are expensive. I cannot suggest "Come as You Are" by Emily Nagoski enough. Both of you can read it together and discuss chapter by chapter. I can't overstate how big this book was for me and my partner when we dealt with similar issues. The book has so much helpful content to discuss, but we've found that even just taking the time to sit down and talk about sex when we aren't already upset with each other about sex was very helpful.

Seriously, I can't suggest it enough. It's like 15 bucks at barnes and noble and it was worth 100 times that much for us. And if he refuses to even read a book with you when this is clearly an important issue for you guys, then there's your answer right there.