My dad is addicted to meth

I recently found out that my dad has been doing meth for the past 3 years, and has recently become highly addicted to it. My daughter is 4 months old, and I feel like I have been living a lie. All of the visits, the cook outs, the gender reveal, the baby shower, family vacations, all of it a lie. I never realized anything was wrong until this past week when we went on vacation for 2 days. I noticed he was acting weird but I thought it was just because he was drinking too much. When we got back from the trip my mom finally told the truth. She has been living with this secret for 3 years, afraid to tell me because she knew how much it would hurt me.

My dad is 57 years old.

I feel betrayed. I feel like me or my daughter is not good enough. I feel lost. I feel numb. I want to confront him about it, but I know that the result will be me never wanting to see him again. I want to help him. I want him to see how he is ruining his life and ours. I want things to be the way the used to.