Anybody have an advice to help me stop drinking and would anybody consider this situation cheating?

I just recently turned 18 but I have been drinking alcohol since the age of 11, which wouldn't of been very regularly at that age though. I can give it up as I have gave it up for the sake of the relationship that I am in now. The other night I got in to a mess and some fella tried to kiss me. I can hardly remember this and had to ask people for information. I know that I pushed him away but i think we kissed for like one second. He came on to me. Im devastated that this happen as I had to tell my boyfriend and he's now very mad at me because a situation like this has happened before too. Would anybody consider that cheating though? Alcohol is ruining my life and am just wondering what tips anybody has to help me stay away for good :( I know one change I can make it go back to the gym. I drink alcohol roughly 1-3 times a week.