Postpartum depression

I have no idea where to turn to. I have a doctors appointment for possible postpartum depression on the 26th but until then I have no idea who to talk to. My fiance has been cranky and an asshole latley my mom has been making me feel like im not doing good enough with my daughter and keeps giving advice all the time repeating the same advice no matter how many times I tell her im trying her advice. And the one person i want to talk to about all this is struggling because the 6th anniversary of her daughters passing at 24 weeks is coming up on the 25th and my whole pregnancy after finding out was a struggle for both of us. Im trying to do the best i can for her and be respectful of her loss and not bombard her when i know shes vulnerable but it all just makes me feel so alone.