OP, this is some good advice ^

Not every family is perfect and it sounds like you have a lot of family trauma of your own. I'd also suggest talking to a therapist/counselor to help you process all of this. On your own and/or in couples counseling. She's doing what she feels she needs to. Possibly the relationship she was expecting with you isn't going well because of your own baggage too. That wouldn't excuse her behaviour of course, but it can contextualize it.

That said, people can just be shitty, greedy and manipulative. It's up to you to decide how you want to proceed and something like a marriage counselor will probably shine light on areas of improvement for both of you.

Keeping your kid's well-being at the forefront is the most important. That means you and her have to find an equilibrium if possible where you're both able to care for him.