Yes, lving with an alcoholic is hard on teh ENTIRE family. My exhusband is an alcoholic, believe me, I know the pain first hand it causes, it takes the person away from the family and alcohol becomes their god. I am sorry you are in this situation. It;s like he's in the home, but absent from your son. Would an intervention work? Not to be negative, but even if they do get better, there is always the risk that they go back to it.
Also you need to think about yourself, what can you do protect yourself. Is there any way you can be more self reliant and not depend on him for every dime he earns. Remember this is a PROGRESSIVE disease, it only worsens. I was living with an alcoholic who could not keep a job. Now he's in jail. I just could not do it anymore.
If you son is open to going to Alateen that might be a good place for him. It helps to be w/other kids who are having the same issues. Unless you have lived it, you cannot understand it.
Oh boy. This is tough. It is not good to live with an alcoholic parent. I fear for your son's emotional state. I fear that he may start to become hyperresponsible for you as he feels like he has to protect you. I fear that he will be internalizing this and it will have a life long effect. It is very hard to leave a marriage. Would an intervention of some kind help to encourage dad to go to rehab? I am afraid if he won't that you will have to face leaving him. It is not good for children to be in that enviroment. Think about it------ this is his same sex parent and how he views a husband and father to be . . . this is not how you want him to view home life, marital relationships and fatherhood. Would an intervention be an option?