But, it's not only a few beers. It's 10-14 beers in less than 2 hours. Alcoholism is progressive and never gets better without treatment, it only gets worse. If things continue the way they are now, what you have now is the best it will ever be.
Putting the wedding on hold is not walking away. Read around on this forum and see exactly what you have to look forward to. If you tie yourself legally to this man, it will be much more complicated and difficult to get out of what could become a very dangerous situation. He already verbally abuses you. Is it really worth it to marry a guy you already have such reservations about?