PPD help

I think I have PPD, but I'm not sure. And I don't know who to talk to about it... I just know it can't be normal to feel crippling anxiety when my son is having a bad day. or to have a emotional break down weekly and wanting to disappear. or feeling like someone else would be a better mother for my child. I feel to weak to be a parent. I feel like I fail my son daily. I just can't do this anymore.