What is wrong with me?

I'm 22. I got married at 20 years old, we rushed into it stupidly. We seperated 2 weeks after our son was born. He is now 7 months old. I am currently 9 weeks pregnant by another person. And for the life of me I can't seem to figure out how to pick a man. The only guys I seem to find want more kids (I'm getting my tubes tied after this one) or they only want to play games. And even though I see it I still hope it works. My life revolves around working 2 jobs and taking care of my son. I have post partum depression really bad but cant take antidepressants for it. So when I have companionship then I have someone else to turn to when I feel like I can't take the crying anymore. Somewhere I can go when I need a break. I dont have famioy that can helo and my ex husband wont watch our son over night or anything more than a few hours. He does help financially when I ask but that's not what I need. Is it bad that I want a relationship with someone who actually cares? I feel like an awful mom for wanting a break away from my son. What the hell is wrong with me.