Lack of sex drive after baby?

Im 8 weeks postpartum, and I legit have no interest in sex. Not with my partner (who including his family put me through so much shit...long story), not for anyone else, not even alone. Its like I have died on the inside but its not bothered me, I feel happy and content. My fiance keeps asking me to have sex wjth him but I cant even stand kissing him and feel violated thinking of forcing myself to have sex with him. I look at my naked body and feel a deep sense of disgust and get even further turned off (gained 60 lbs despite trying not to, lost only 30 and cant lose any further). Has anyone else experienced this? Shpuld I be concerned lol