that although he is saying that he knows he has been abusive, it still feels like he is still emotionally manipulating me.
To be technically correct he kinda is, but probably not in the way that's most obvious.
people with BPD have very strong emotions and a high sensitivity for negative reactions, they see even neutral or passive things as negative and attacks on them.
They also often have fears of being abandoned, that if you are not there for them and their needs whenever they want it means you don't love them and you will leave them. Their pushing you away, the saying nasty things, is
a disordered attempt to get your attention back by triggering in you the same abandonment they feel themselves.
This is the "manipulation part", they have a goal and are trying to get you to act differently, they don't state their needs to come to a mutual understanding because they probably don't know how to, or even if they do any perceived negative further increases frustration and they go back to their angry ways. There's a whole book about it called "I hate you don't leave me".
He tried to make me believe that I was being abusive.
They feel abused, they feel you are disregarding their emotions, disregarding them. They feel the pain caused by not having your total undivided attention to themselves as being directly caused by you. You are not being abusive, but
it feels like you are to him.
It feels very real to them, as much (or most likely even more intensely) as you feel it yourself. Their underlying assumption is not correct, you were not being abusive, you needed to focus on something else, and that's ok.
Anyway, I'm saying all this to hopefully give you a glimmer of understanding to help decide how you want to move forward.
I don’t know where to go from here.
What do your feelings tell you? what does your conscious mind, your inner voice say?