You need to ask for councelling – not just about the booze but about life and communication and obsession over work.
I am sad things are rough for you – but I suspect they have been even rougher for your wife and child for a very long time.
It seems very improbable that your wife would have left you with no prior warnings, no prior discussions, no indication she was struggling herself. Which makes me wonder if you ever took her seriously or listened to her, if you ignored her or dismissed her views. However well you meant in trying to have a good income it still looks like you put yourself first in choices and in booze, or at least have become a workaholic with no awareness of his self destructiveness or its affect on others.
You say something like ‘there is no impact other than financial’ well clearly that’s not true. No one just ups and leaves on a moments whim with no backstory. Also just how bad is the financial impact you imply is trivial? She seems to say you are moody (which implies unpleasant to deal with) – why would she lie?
You say there has been no holiday for, what was it, 17 years? (not going to trace back to look). So no holiday for her then? Or for your loved child?
You were a lucky man – she really loved you to stick it out for this long.
I hope it sorts. I hope you all feel better. I hope you stop putting yourself first, using the excuse of work is more important than people or love. Sorry to be harsh, but its the only way of helping really. If this relationship is permanently down the pan, at least learn from it so the next one goes better.
All the best. I lost everything a long time ago. I know how shit some stuff can be. Sometimes horrible experiences end up saving you.