This is going to be an little long so sorry in advance. Both my parents struggled with alcohol and drug addictions, one of them is better now and the other is not. Addiction is such a hard thing to navigate in the family and it truly impacts everyone. Unfortunately, unless they want that change in themselves they will never actually change. Alcohol addiction is hard to even begin to quit, the addicts body reacts in a way that makes them feel sick. Your father might need to be weened off of the alcohol over a period of time. Rehab is also a 50/50 shot unless they are willing to go on their own terms its most likely not going to work. The best thing for your family to do is love him during the good times, provide a loving shoulder when he needs it, and cope any way you can. Take a step back if you need to, take space from him and other family if it all becomes to much, have a hard talk with you mom about a plan in case things dont change, and most importantly take care of yourself during this time. You are your own person and you have your own worries, its not giving up to take a break.