Fiancé told me he was depressed because I’m fat

I was 30 pounds lighter when I met my FH 3 years ago. I was also underweight and had an eating disorder helping keep my weight low.
I know 30 is a lot to gain. Part of it is new medicine, another part is me becoming sedentary over the pandemic, and I love dessert. I order it on the weekends but I still generally limit myself. I’ve become sedentary largely because of my work schedule as a lawyer. Working 50+ hours a week, planning this wedding entirely by myself in 8 months, and litigating a case for FH’s mom so we can keep the house we are currently living in. FH also gained about 20 pounds since we met, and I thought he still found me attractive, I really look like a normal weight just soft.
FH was acting quiet all week and going down to the bar more than usual, and finally spilled last night what was wrong. He told me he was depressed because I’ve gotten so big. He didn’t want to be around me because the way I look actively bums him out. He said that every time I ate cookie dough I was disrespecting him, because I didn’t care what he felt when he looked at me. He asked why he wasn’t good enough for me to try to be attractive.
My eating disordered brain just came flying back like a slap in the face. I told don’t worry I know how to lose it just give me some time. Now I can’t eat in front of him without crazy anxiety and every time I look at food I think about disrespecting him. I try and keep my chewing silent so he doesn’t hear me eating
And I don’t know how I’m supposed to walk down the aisle in a mermaid dress in front of all those people knowing I look like a fat cow and I’m actively depressing him. I feel sick every time I look at myself now and I’m supposed to be walking down the aisle in a month.
I don’t know what to do, I feel unbelievably lost and uncomfortable and alone. Someone please give me perspective!