Weight and sex

I put on a lot of weight since my bf and I started dating, about 40lbs. Our sex life has gone down the drain since I'm self conscious about my body. Last couple of times we've tried to have sex, we didn't even finish because he couldn't stay hard. He has told me my weight bothers him. I am trying to lose it but it's hard with pcos and binge eating disorder. I feel very unattractive because he can't even bring himself to have sex with me.

Idk what to do or how to even react. I know I will continue to keep trying to lose weight, it just sucks.... I even tried dressing up sexy the last time we tried, and he got hard, but lost it not long after. Now he says he feels like there is too much pressure to have good sex.

Anyone deal with this or have advice? We've talked about it and want to be together. Everything is perfect except the sex part right now.