8 weeks PP and still depressed

I guess I’m writing this because I feel safe here. My son is 2 months just about and I’m still depressed. When l was 9 months pregnant I found out his dad cheated on me and gave me chlamydia. Mind you we live together & I wanted to kill him and leave him but I come from a broken home and I wanted my son to have different and I truly love his father. He only did it once but that was enough for me to still resent him. Granted besides that he’s definitely the best man I’ve ever had. But now it just seems like we’re always arguing and the communication is bad. I feel like we don’t understand each other anymore. And I’m just overwhelmed because I’m just sick of it all. And it’s adding to my depression. It’s not all bad but I’m just tired of being sad all the time. I’m trying to work it out but it’s harder than it should be