Welcome to SR Demijohn and thanks for writing that all out - it can definitely be beneficial to see it all in one place. Since you have asked for some suggestions, I'm happy to offer a few.
First off, you mention "triggers" and causes many times throughout your post. I personally don't feel that one can actually know what causes their addiction - you simply have to accept that you are an addict/alcoholic. Most addicts go t through a phase where the delve deeply into the "root causes" of their addiction, when in fact they are looking for a cure so they can go back to moderated/controlled drinking. I know I did for a long time, years in fact. The only way out for me was to unconditionally proclaim/accept that if I drink any amount of alcohol, bad things will always happen eventually.
That's not to say that most of us don't have underlying issues - depression, anxiety, the list is long. And indeed, some "self medicate" those conditions with alcohol - and it even works sometimes for a little while. But the only way you can ever have a chance to deal with those issues is to stop drinking entirely first. Therapy and meds and everyting else associate with fixing your mental health is ineffective when you are drinking. Alcohol is central nervous system depressant, so if you have depression too of course you are just pouring gasoline on the fire.
The other thing about "triggers" is that they are really just part of life. Family problems, work problems, personal relationship problems, money problems, the list is long and it never goes away. So it's not really possible to avoid them all - the key is that our default reaction is to drink/hide/run away. And its' not really even the alcohol itself that is the main problem - it's our choice to avoid rather than facing the situation head on. And its probably one of the hardest parts about quitting as it signifies really major change in your life. And hard work.