Hi Done4
I'm sorry to hear that you are not getting understanding from your exgf. You are definitely not alone in that. I'm glad you found the forum, because many of the members here DO understand what you are going through.
Even though your ex hasn't been diagnosed, the label isn't as important as the behaviors that brought you here. It's really difficult to deal with meltdowns, especially when they get violent. And the hookups without wanting more don't surprise me. If BPD is a factor, that would make a lot of sense, as pwBPD are often comfortable in relationships that are sometimes close, but not too close, so that the fears of abandonment/engulfment won't rear their heads as often.
How long were you together? Are you hoping to rekindle the relationship?
Keep writing. We're here to help.
heartandwhole