Welcome to SR!
I am sorry that you are frustrated, angry and having to live with all that drama.
Alcoholism is a family disease. It affects everyone in the family.
You are old enough to attend Alanon meetings for support. You will also find support and information here. Alateen is available for your younger siblings.
The three C's of alcoholism are:
You did not cause it
You can not control it
You will not cure it
It may not feel like it, but your mother leaving (with children) may be what it takes for your father to hit his bottom. Alcoholics wont embrace sobriety for anyone but themselves. They have to want it more than life. Otherwise, they remain addicted and their life is beyond control.
Do you have a counselor or another adult in your community that you can share your concerns with?
Keep reaching out for help. We care about you.