Good morning and thank you for writing to us. My name is*****'d like to help. First and foremost, your boyfriend's behavior is not your fault. He is the only one in control of his actions, including the amount he chooses to drink, and even the behavior he displays while intoxicated. There is rarely, if ever, a good excuse for the aggressive and verbally abusive behavior he displayed including raising his fist to you as I am sure it was intimidating, disappointing, angering, and sad to witness. I am very proud that you advocated for yourself in that moment and made him leave as he was acting erratic and your safety was important. Furthermore, I am very proud that when you called to check on him, you discussed his drinking and that you would like for him to stop. It sounds you handled everything exceptionally well.
There are many reasons that people fall into a lifestyle where their drinking or substance use becomes an issue. Often times people who are using substances have a hard time pinpointing exactly why they do it or where became a problem. Many people simply turn to substances as a coping mechanism and then become addicted, meaning they suffer physically, emotionally, mentally when they do not use or do not use in certain circumstances (like socially). Quite frankly, people are often in denial about their use and the implications they suffer as a result of it. Perhaps the lack of intimacy has been a factor in this but as you point out his behavior has also changed and escalated which more than likely has a lot to do with numerous factors beyond intimacy. And yes, it is not surprising to hear that you have grown distant from him physically as these outbursts have increased. Kind of a vicious cycle. But the fact remains that your boyfriend is the only one who can take responsibility for changing his patterns of behavior.
Ton offer him the most help, I would continue this conversation with him. Point out that you are supportive and will be by his side as he gets the help he needs but do not shoulder the burden for him. Consider offering ultimatums that if his behavior does not change by a certain point in time, then you will have to consider ending the relationship because the pain and fear it causes you. But please understand that unless he fully engages in treatment because of his own personal desire for positive change, it is not likely you will see lasting changes in his behavior. This is because motivation and desire are large factors in someone's success getting treatment. He has already offered you an excuse about why he cannot quit and this demonstrates some of his resistance to change at this time. However, you have to stay firm that his behavior and escalation of behavior is unacceptable to you and unless he seeks help, he relationship is in grave jeopardy.
I wish you all the best as you continue to engage in this effort with your boyfriend. Hopefully, with continued conversation and support, he will understand how much his choices and behaviors are affecting you and your relationship and he will choose to get help. Please let me know if you have any additional questions or need help finding resources to offer him to get him started on his path to change.