He did reply and just said "there's nothing wrong with you and I am not going through this again"
The sharing of porn stars is symptomatic. The REAL problem is this: a total lack of empathy and care for his partner and her feelings.
There are so many women on here who have been through similar, and come out the other side. I have been in a similar position (minus the child). Right down to writing him an email to try and explain my depression! I'd moved to a different country to be with him, and was desperate to make it work. When I got there, I realised he was a total arsehole, but I wouldn't come back because I was too proud and thought people would laugh at me. I wasted five years in the end.
I think if you left him, you would notice a big uptick in your mental health. No wonder you're depressed: you have no family and friends nearby, no support at home with a new baby, and a partner who invalidates your feelings. Anyone would be depressed in that situation.
When I left my ex, my depression and anxiety went away. I have never needed treatment since. When you start reading these threads regularly you see how many women are medicating themselves to stay in shit relationships, and it's horrifying.
Is your mum still about? Do you have a sister or a brother you could say with? Maybe just go home for a few days for a visit, and see your friends and family. It might lift your spirits.