I didn't have time to read the whole thread, but I'll share my experience and you can take it for what it's worth.
I am going to be 30 next month. At the age of 24 my drinking was about the same as yours. I wouldn't drink everyday, or even every week, but when I did, it was always a lot. It was to get buzzed/drunk. I wasn't interested in drinking for the taste.
After school and I got a better job and started pulling in some decent money, my drinking expanded to everyday about the same amount that you are drinking right now when you do drink... everyday.
Fortunately, I caught myself and quit. But, it's a progressive habit. As you drink you will build up a tolerance and you will have to drink more to get the same effect. I told myself for several years "Oh, I'll grow out of it." I never did. I had to step up, man up, and quit despite my cravings to continue.