I think I have postpartum depression

I love him so much, but I'm having thoughts that having another baby was a big mistake, I can't believe I'm even writing that is never say it out loud. I thought in can be super mom and do it all but I can't. My husband is no help, I'm tired, frustrated , I live off of diet soda, crackers and xanax. I don't want to do anything and I just want to cry. I love him so much and I know it will get better but I'm also so lost and just want to give up