I couldn't wait to go to college when I was your age. High school was okay, but you have so much more freedom in college. I remember during the first week of my freshman year (before practice and classes started), I'd run in the middle of the night just because I didn't have my parents there to worry about me. Yeah, I know I was a rebel haha.
The good thing about college was that it helped me transition to the "real world." My parents were still there if I needed them, but I had the opportunity to be on my own schedule, take care of my own responsibilities, make some mistakes, etc.
I was also able to be myself and figure out what I actually wanted to do with my life. This part was scary (in a good way), but turned out for the better. When I look at people I went to high school with that didn't go to college, they are still stuck in high school. Living in the same town, married to each other, working at Wal-Mart or whatever because they comfortably settled.
I think most people who are unhappy are that way because they settle. They settle for what they are told by their parents, peers and society in general. You said yourself that you've "seen old people pretend to have fun in their retirement, but who can't help but feel sorry for them in their pathetic state." This is an assumption on your part. How many older people do you really know?
The thing with high school is that there are too many people telling you what to do. It's up to you to be happy. You will be fine. Pretty soon you won't even care that they didn't put you in the yearbook ;)