You sound like such a thoughtful caring person, to want to make such a positive difference in your ex-boyfriend's life. He is fortunate to you so invested in his well-being.
Personally, I was somewhat of a heavy drinker throughout my 15 year battle with depression (which ended over a decade ago). Having been on both sides of the fence, I recognise my alcohol dependency as a self-medicating thing. Changing the chemistry up there, through alcohol, can be a wonderful form of escapism but in depression it becomes a bit of a catch 22, seeing that alcohol is well documented as being a depressant. It's a cruel cycle. When my brain finally changed for the better, I suddenly stopped drinking altogether at that point and actually couldn't even stand the smell of alcohol. Weird! I choose to change my brain, through alcohol, only a few times a year nowadays. And as a mum who has experienced the traps of depression and alcohol in my younger life, my kids are well educated on the importance of managing overall well-being (body, mind and spirit). Finding balance between the 3 is definitely a management thing.
The reason I mention my experience is because the depression aspect of your ex's issues might be the thing to address first, more-so before the drinking side of things. Perhaps the core issue isn't necessarily his dependency on alcohol so much as it is about the dependency on a way to change his brain chemistry. Wondering if you have suggested he get onto the BB forums, if he wants to feel support whilst remaining anonymous. It could be a good way of him gaining support from something other than alcohol. Seeing a lot of people here have had experience with managing depression (therapy and meds), perhaps the forums may act as a guide for him, a guide besides yourself. If you're unable to guide him into counselling, perhaps someone on the forums can. Anyhow, worth a thought.
Mentioning to your ex the impact of alcohol on depression as well as the mention of gaining access to all the great things Beyond Blue offers, might have him looking at the possibility of managing the 2 issues at the same time (cutting down and stepping up, to get help and support).
Take care of yourself LeeA18, you are a beautiful person.