Gerri_EK10,

You seem to be caught in a frustrating gray area, trapped. The push-pull behavior is pretty typical BPD. Did you learn that he was diagnosed, or were his behaviors fitting the profile?
Though you're not in a romantic relationship, you're still living together and sharing a child, though I imagine that you are doing most or all of the work. That's even harder with a man who wants you to mother him, romantically attached or not.
In general, your situation has been shared similarly by some members here on the Staying Board-- living with an Ex, co-parenting, and unable to move out at the moment. I lived with my Ex for 4 months, after we were done and she could comfortably move. It was nerve-wracking!
We have communication tools here which can help reduce conflict, calm his emotional dysregulations, and also teach you to assert boundaries in a positive way. Lastly, there is the aspect of taking care of yourself. That often gets lost, and it must be even harder with a child who has medical needs and requires a full-time care-giver. Is your child ok in general, though?
Take a look here to start, Gerri_EK10. These apply to any person with BPD traits (SO, Ex, parent, child, friend):
Communication tools (SET, PUVAS, DEARMAN)It sounds like a tough emotional place to be, but when he threatens you that you have to move out, do you feel safe?
Turkish