Drug Rehabilitation that works

my parents are both addicts and now im worried i will be one too. i dont drink now but should i just stay away from it? are my chances higher than others to become an addict?

I’ve know my bestfriend for 10 years and we’ve been roommates for 6 years. All those years, he would drink at least twice a week, mostly during the weekends. I have tried to be supportive when he’s been sober for 6 weeks…been going to the gym with him; he’s lose the beer belly; praised and thanked him every night for such great time together, eating healthy, etc., but he relapsed. He says that he goes through this phase of stopping cold turkey for weeks and months…then he’s back into the “old habit.” I don’t think I’m doing him any good by buying his alcohol. I try not to be around him too much when he’s been drinking and we hardly talk when he does. I buy his alcohol and then leave him be for days. I don’t know what else to do. He has expressed interest to go to rehab (like Mt. Vista Farms) but we both know that it’s expensive and no one can help us financially. Should I feel bad if I kick him out of my apartment and leave him hungry & homeless? What can justify the guilt that I would feel when I do so?
CORRECTION: It started gradually with 2x/wk, then continued on everyday.

Alcoholism is in my family but i didnt clearly understand it until now. Grandfather was a terrible alcoholic and mother has inherited the disease but avoids it by not touching a drink in 25 years. If uncle (250 lbs) touches one drink, he gets mood swings and very aggressive.

How do I know if I will inherit this disease and if so, what are the characteristics i should be watching for in my drinking life?