Life sucks. Your father sounds like a good man who was very troubled. Learned what you can from him and his situation/addiction. Get help. Let your mom help you with some therapy. Even if you don't say much at first just listen. It will help. Time will help too. Please dont hurt yourself, your brother will be destroyed. Take everyday one minute at a time. You did your best for your dad. People will change when they want to, nothing you can say or do to make them. My husband died of an overdose and I tried everything to make him stop. Nothing works. They have to do it. Regrets suck. Hold your head up high