Welcome to SR ranae1221
I can understand why this is so frustrating for you. I know that you want to do the right thing for your father. But at what price your willing to pay? Look at the stress it has brought it you. Its hasn't made you feel better. You have too much on your plate... you need to deal with things one at a time. You just lost someone who you deeeply cared and loved. You need to heal. On hand its good your dad is starting a program to sober up, on the other hand its not your responsibility to make sure he's not drinking. You really need to stop letting him make excues because excues doesn't change anything. If he can't do it, then he can't do it. If he can.. hopefully this is the last time. Stop going aroung in circles.
I understant why your siblings and your father's sisters do not want anything to do with him because at some point you get so sick of it that the excuses and short term "bliss" aren't worth it. My dad tried stop drinking once and didn't last a month and now he is doing it again.. but its obvious he is still drinking. My dad has burned bridges too.. my siblings and I do not want anything whatsoever with him. I am already at the point that I could care less what happens to him. I think the reason why your mad at yourself is because deep down you know that this is too much. You know this isn't right, you don't have to deal with this. If you don't want to be alone, find something that can allow you to take your mind off of things for a little while. Something that you enjoy. If its being around people, spend your time with people that isn't your dad. You need to get him out of your house. Have a friend stay over or maybe get a pet. Pets are great companions. Considering the condition your dad is in... he is too unstable for you. Him being around you will and is making you worse. He is toxic for you.
You should give the alanon meetings a chance, shop around your bound to find one that makes you feel comfortable. And if it doesn't, that's okay too. If you prefer therapy, that's good too. Or maybe posting will help you. Posting and just reading other people's stories on this forum has helped me so such. Everyone has different way of dealing with these things. All i hope is that you find what your looking for and begin your progress of healing. My thoughts will be with you. Take care of yourself. Keep posting.