I also struggled with my parents' drinking, in fact I used to dread it when Dad came home with beer because they'd be there all night drinking. Mum was nasty, Dad just more mellow. It upset family life for me and my sisters when we were in our teens.
You're a bit older, more mature now. Have you talked to your mother about this? Or is it something you can't raise with her? You might also want to tell your father how you feel, but focus on being worried about him, not just on your own feelings.
It won't necessarily help him, or get him to admit he has a problem, but you will experience some relief and possibly not feel the need to act out.
I'm a dedicated atheist too, but I'd still go to AA if I felt I needed it. Give Al-ateen a go, you can then judge for yourself, and as you don't have many people you can talk to I'm sure you'd benefit from meeting other's in the same situation.