Body image issues getting in the way of my romantic life

I gave birth eight weeks ago. At first I was okay with how my body changed and knew it was from obviously having a baby. Then weeks went on and I starting really resenting what I saw in the mirror. Then as more weeks went on and despite working out, breastfeeding, and eating healthy I wasn’t losing any weight I hated myself even more. I don’t feel sexy or attractive in any shape or form. My fiancé wants to cuddle and make out and have sex and I want nothing to do with any of it. How am I suppose to want to have sex when I feel so uncomfortable in my own skin? I’m struggling and I don’t know what to do.