I'm so sorry, man. That sounds like a hell of a situation to be going through.
I've had a few of those kinds of relationships through the years and I know how much strength it takes to pull yourself out of them. The best thing you can do is to avoid all contact with this person and be patient with yourself. It can take a while before you feel "right" again, so don't be discouraged if 2 months from now you're still dealing with some feelings. Definitely have the right idea by setting goals and focusing on improving yourself, but make sure the validation comes from within.
I remember the last relationship like that I had, all the warning signs were there from the get-go. The extreme neediness, hyper-sensitivity, the push-pull dynamic, the gaslighting, etc. I stayed around longer than I should have, because I was hoping to have that one moment where they would slip up enough to make it easy for me to move on. Obviously, that was a dumb idea, because the further along you go into these relationships, the more dependent on them you become. These people are highly complex, and it's a pipe dream to think you're going to have them "come clean" about their bull****. If they were capable of that, they wouldn't be ill in the first place, lol.
The hardest thing is trusting your judgement. It's so easy, especially with how manipulative they are, to be seduced by doubt and think somehow it was your fault or that they can change...
Nah, the person is cooked and you need to get the hell away from them. I promise you the more time you spend away, the clearer things become. You're going to look back at this years from now and wonder how in the world you fell for their nonsense in the first place.
the problem I get is that one or two years later I feel like this time has been wasted and I've still not met anyone better. i start to think all that nonsense would be better than all this emptiness. so idk. till something better happens just kind of in limbo. I try looking forwards but theres nothing there.
"I take what is mine. I pay the iron price."