Welcome. I hope you find what you need here. I am new here too. I have lots of the same feelings you describe (tired, sad, lonely, disappointed, shocked). I also was cautious of alcohol because my parents both struggled with alcohol.
I am totally ok with you thinking it's not a disease. I personally think (for me) it's some combination of biological predisposition and role modeling/environment. And an attempt at not feeling emotional pain.
Please post more.