What you feel resonates with me so well! I've hated company social activities my whole professional life (and it's a long professional life!). I hated it when I was young and I still hate it when I'm much older. I hate these activities with well known colleagues, and I equally hate it with people I've spent two months with. I just don't see the point in spending a night with people I barely care about. Of course, there'd always be one or two colleagues who I'm on the same page with, but I'd rather catch up with them one on one and have a heart-to-heart conversation over a coffee instead of having a meaningless social chat.
And yes, the drinking! I don't drink and hate to see people's puzzled faces when they find out that I don't drink and I can see they want (and can't) ask is it because I'm pregnant, or perhaps on medication or else. It just doesn't occur to them that someone may not be drinking simply because it doesn't taste good and it doesn't do anything for me (in terms of numbing my feelings or giving me relaxation).
So, I've found a solution - somewhat - of rarely going to such company activities, but if I go (if I absolutely can't refuse because of company politics) I'd just go for an hour or so and will leave around the time when everyone is getting too drunk for me (sober) to stick around. In fact, a couple of months ago I read an article by a well know New Zealand journalist who doesn't drink and faces the same dilemma and she wrote that she does exactly the same - attending social drinks now and then and leaving early. That was good to know.
And, finally, most importantly, over the years I learnt to stop apologizing and explaining myself for not drinking and leaving early. As long as I'm not intentionally offending anyone why would I need to explain myself, right?