I surely do relate to what you are sharing here, and I would encourage you to go to an Al-Anon or Al-A-Teen meeting to find out how to deal with your dad's drinking. I'm in AA, and I can tell you that our Big Book text reminds us that we don't label another alcoholic, that is one disease that they must admit/diagnose for themselves. He's obviously got a problem with drinking, but try hard not to label him, he will resent it and resist any type of suggestions you have for him to get help.
Get help for yourself so that his ongoing drinking will not cause you further angst. The first post stated: "I didnt cause this, I cant control it and I cant cure it." is the mantra of Al-Anon, and they learn to detatch from the problem with love. You will still love your dad, but you will accept your own powerlessness in trying to change him. Get a solid conscious contact with your own Higher Power, talk to that HP and share your concerns and do this everyday....then trust Him for whatever the outcome.
I'm sure your dad is aware of how upsetting this is to the family, and he is still in denial that he has a problem. Seeing you get help for yourself will show him that he too possibly needs help, and when he asks, you can suggest AA or rehab to him. In my experience, interventions are very problematic. Unless everyone involved is of one accord, there will be divisions and the drinker will see that they are not united for his cause. Still, those that are united usually have good results. Discuss it with the rest of your family, have resources available for your dad and your family, have your facts on drinking (printing them out is very good) and present a united appeal to your dad. Be sure that you all agree on the same way to do this.
For the you and the family, Al-Anon and Al-A-Teen are very helpful. Tap that resource and become a participant in those meetings. I assure you, it will help you immensely.
Good luck, PF, I will pray for you and your family.