HELP! Functioning alcoholic... maybe

I need some advice. My boyfriend likes to drink. When we met I knew that. However I didn’t really know the extent of his drinking. Over the past several months I’ve gotten to see just how bad it is.

He’s a musician, what musician doesn’t like to drink right? He can drink all day, which he does about 90% of the time. When I say all day he will have a beer at around noon and continue on through the day, when about 5 pm comes he drinks the hard liquor mainly whiskey. He’s even admitted to being a functioning alcoholic.

He is seriously the sweetest most caring guy that I’ve ever been with but when he gets what he likes to call “lit” he can become an asshole. On 3 separate occasions I’ve witness it myself. The first time I thought maybe he just had a hard day, but just recently(yesterday) was the third time he said some pretty rude stuff to me.

I was pretty mad with him so I didn’t call or text like I would usually do in the morning. Were long distance so we try to talk as much as possible thought the day to compensate. Anyway I told him how I feel about him drinking and becoming an asshole and somehow it turned out to me being overly sensitive.

I’ve always in past relationships ignored the red flags but this time I’m thinking this is one. As I said he is the sweetest most caring man I’ve ever been with. But I’m not sure if I can handle his drinking. I’m not the one to tell a guy what he should and shouldn’t do so I won’t tell him to slow down on the drinking or stop. Honestly I’ve tried but it ended in him basically making excuses and saying I was overreacting.

I don’t know what to do. My aunt has been with her boyfriend for over 18 years and he is also a functioning alcoholic and I see what she has to deal with.

Sorry for the long post. I need advice. Help.