@eddieddie,
So you are back with her then
Kids are important, your little one is important, who you choose to date, live with, love, marry is going to be your choice. If you feel that this is/was a toxic relationship and one that gets you reeling then you are probably right.
You are both young though, so nothing makes you look like an idiot, it's called learning. You did choose this woman, and you did choose to stay with her once she cheated, and you choose to go back, everytime she gets in-secure (which when you are pregnant, you really go nuts with the hormones), and I don't think it matters what we think or who is right or wrong does it? What matters is what you think and if you two can work it out or not.
I'm not trying to do anything hun... Just no sense getting upset, mad or anything, better to jump past all that crap, it just eats at you.
Do I dabble in counselling? IDK maybe, sort off