Hi, I'd like to help you with your question.
I think you are right when you suspect your boyfriend is an alcoholic. When he drinks that often and to the point of being drunk and cannot do without alcohol, then he does have a problem.
The issue with alcoholics is that they deny their drinking problems. So when you ask, are you having a problem with alcohol, they will say no. It is this denial that needs to be worked through so once they realize they have a problem, they can start to recover.
Confronting him will only go so far since it sounds like he is in denial. But you can try an intervention, if you feel you have enough support to do so. An intervention is when you and other people affected by your boyfriend's drinking all get together and, with the help of a therapist, you confront him with his drinking problem. Here is a link to help you get a better understanding of how an intervention works:
If you chose to not do an intervention, then it is left up to your boyfriend to figure out he has a problem. Usually, this means hitting bottom. By that I mean things must get so bad in his life as a result of the drinking that he has no choice but to see the drinking as a problem. For example, he may lose his job, lose his friends, and his health. Once a person sees that they have lost everything, they begin to understand it is because of the drinking. It is then the denial is broken through. Some people do not make it to that point. They become too sick or ignore the warning signs and keep drinking until they die.
At this point you can chose to leave the relationship. It would be difficult, but it may be necessary. And it may help him break through the denial.
If you so chose, staying in the relationship means that you will have to deal with your boyfriend's use. Some people feel that if they stay, they can help. But usually alcoholics do not want help. They want someone who will support their drinking. That is where it becomes difficult for you. You can seek out support through programs. I am not sure what programs are available in your country, but I can offer you some links to ones here in the U.S. and you might be able to find sources on line or similar programs in your country.
Here are some books that may help you as well:
Get Your Loved One Sober: Alternatives to Nagging, Pleading, and Threatening. by Robert J. Meyers Ph. D. and Brenda L. Wolfe Ph.D.
Addict In The Family: Stories of Loss, Hope, and Recovery. by Beverly Conyers
You can find these on Amazon.com or your local library may have them for you.
I hope this has helped you,