Hi EC,
The anger I feel is massive and at the same time I feel sorry for him.
As the posters above rightly said, it is normal that you go through this phase, it is part of the process. It should be temporary.
I know that I would be better off by severing my ties to him but then again I do not wish to alienate myself from my mother.
As you are revising your judgment about him, you feel that you should modify the distance between you and him and you are right. And this may impact the dynamics/triangle b/w you and each of your parents. It may take time to find the "right distance", but you will find it eventually.
I also feel like I do not want to abandon him because after all it is not his fault. He has a problem for which he is not to blame.
See? You are dealing with the "right distance" stuff

. You may be partially right in saying it is not his fault (you may say why after you have studied in detail his own backgroud/relationships when he was younger. And on the other hand, at a certain age adults may bear a minimum of responsibility (at least this is what I believe).
So it is very hard to draw a line b/w responsibility of s.o. for their behavior on one hand, and the "predetermination" they are subject to, due to the history of their ancestors.
As far as I am concerned I could only handle my father's past behavior by doing genealogy research about his family. It put some many things in perspective

...
Anyway you are on the right track with this board. And keep reading, I wish I had read more before starting my analysis...I would have wasted less time...

Oh well
-ResilientLady