I know part of you wanna stand up for your family by just beating up that man and seeing him fall and make him suffer, trust me I know that feeling. But I don't think that is the way, becuase if you do that you are no better than him, violence and revenge is never been a solution, so besides praying, you should try everything you can do to change your father's mentality, if he had bad habits like drinking... trying to stop all of his addictions and spend his time more with his family will help him, may be you don't know what is inside of him, he might have his own battles, you know as a men we are obligated to suppress our emotions and take it as a man, so try your all possible ways to change that man, may God be with you bro.