ThreeForty22,
Welcome to Sober Recovery, a wonderful place, with, as you can see, lots of support.
Now on to the topic of your dad.
IMHO, it doesn't change a thing. You know. You can't fix him. It answers alot of questions.
What I would do, seriously, if you feel that it has, in the past contaminated your relationship with your mom, sit down and talk with her.
It may be a relief to her, that you DO know, it must have been difficult for her to keep this hidden, and she was porbably worried for you all the time you were growing up.
JMO
Hugs,