I think im abusive?

I know this might be a stupid post because I probably should be self aware by now. Its just in my head everyone thinks like this and is just too scared to admit it.

So for some background I have known them for about a year. Before we dated I made them aware that I can be a manipulative person and that I didnt want the relationship if they couldn’t handle it.After a few months of debating on what we should do about our relationship ( date or not/ setting boundaries) we eventually ended up getting together. The first week of our relationship was good we were both happy and there were no fights, but after that there were small things that would upset me, I was aware they were small and not large issues but they were still issues so they mattered to me. For example I was paranoid that they liked their best friend more than me so we got in a fight about it, I didnt have any reason to believe this other than the fact they knew them longer than me and they call alot. My ex is a very sensitive person and very easily manipulated, me being angry will make them sad but If i say that im sad they feel guilty. Ive pryed information out of them so that I would know what hurts and what I can or cant use to win a fight or get the reaction I wanted. I know what words they hate being used to describe them and who they hate being compared to, along that I also know the flaws they have that they dont like to be mentioned ( personality flaws, I would never attack someones looks thats insane) I love them deeply but I knew they would leave me someday, so I needed to be something set apart from the other people they knew. I willingly manipulated them into being emotionally dependent on me to an extent. Even if I was the cause of an argument somehow it always ended with them apologizing to me for their wrong doings. I willingly and purposefully took advantage of a vulnerable person and I don’t think that makes me a good person. I would often tell them that “ if you were anyone else I wouldve left ages ago” in order to make them feel special, make them feel as if I need them while innreality i was manipulating them into needing me.The idea of them liking someone more than me honestly makes me sick. I hate to say it but ive even had thoughts of hurting them when im angry with them, I always refrained from that due to the thought they would leave me. We have since broken up but we’re still friends, I understand im not a good person but I dont know If i was or am abusive. I dont want to be a bad person but I dont know how to change, because manipulation benefits me, and if anyone else was good at manipulating wouldnt they take advantage of that too??

Thank you for reading this please dont have many negative regards towards the way I act because I am aware that Its not good. I just dont know how to become a better person though.