Fiancé isn’t being supportive

I was recently diagnosed with postpartum depression I knew I had it before I was diagnosed and I told my fiancé that I had it and he told me to stop over exaggerating it’s just because I’m tired, well the past 2 nights have been really bad for me I’ve been staying up until 4 am crying and then I have to get up at 7 am to take care of our son last night I woke him up while I was crying, I didn’t mean to and he got really mad at me and said it isn’t fair for him to have to stay up this late because he worked at 6am the day before and he was tired but after making me feel even worse he let me sleep for a few hours, before I fell asleep I was having really bad thoughts about leaving my son with him because I feel I’m an awful mom and they would both be better off without me, I’ve been crying on and off again today and he keeps getting mad at me and asking me what the hell im crying for, he just doesn’t understand and he isn’t being supportive at all I feel like I’m all alone and I have no one I can talk to