I just realized that I have been an abusive, manipulative, and narcissistic partner, what can I do to change it?

I have been seeing videos about relationships and it’s been an eye opener to me. I always complain that whatever it is that is not working for the relationship is because of my partner, that he’s ignoring me, not making time, etc etc.

And it’s unfortunate that I don’t actively know that I am acting the way I do because I am so focused on the intense feelings that I have and think of it as valid, without considering how I am saying it and showing it to my partner

I do not want to be this kind of person anymore and I want to work on to be a better partner. What should I start doing towards being that?