Partner watching porn alone at work

Before anyone jumps down my throat I want to make it clear why this has hurt me, I had my baby girl 5 months ago I put on weight more than I’d like to admit. I’ve just saw that my partner of 2 years has started watching porn on his own in work, now I wouldn’t have a problem normally but after having my daughter our sex life is out the window I’m rather insecure about my body but I do try to have sex with him he just never seems interested, now I don’t know how to approach this as I’d probably watch it with him but knowing he’s getting off watching another girl is kinda breaking my heart looking for advise.

Please no nasty comments