I completely agree with your approach, I went through a similar experience with my mother.

If your father is not willing to learn from his mistakes and grow as a person, you owe him nothing, just remember that.

Don't allow him to manipulate you with the 'I sacrificed everything for you!' approach, my mother tried that many times too. A parent is SUPPOSED to sacrifice for their children, that's a given. No parent gets an award for doing what they are supposed to do, and a good parent will never make their children feel guilty for it.

I spent my 20's giving my parents the benefit of the doubt and trying to be a 'dutiful' son, but neither of them is willing to own up to their mistakes or improve, so in my 30's, I severely limited my contact and effort with them. My mental health is much better for it. I also had therapy in my 30's, which was long overdue, so I recommend this to you also.