Well, I got my first kiss/make-out session when I was six; but concerning the other things you mentioned, I don't believe it would have made much of a difference if I were never a JW. I think many ex-JW project this fantasy life of what a non-jw childhood/adolescenthood would be like that bears little resemblance to the reality.
I remember being upset that I couldn't join the school band (because they did patriotic songs) but, years later, when I heard how terrible they were even after years of practice, I was glad that I didn't join; what a waste of time that would have been!
Another big issue is sex and dating. Unlike many JW kids I had worldly friends and even most of my JW friends were total hypocrites who led double lives. The first thing you should know is that if you are a girl, your first time with a boy at that age would have been extremely disappointing. Most teen boys don't know the first thing about fucking (some can't even find the right hole). So you didn't miss anything. If your a male, yeah, you missed something, but it wasn't anything that you couldn't enjoy better later down the line. Most teen 'relationships' are so superficial and short lived, they aren't worth the effort involved.
College? Just be grateful you aren't saddled with tens of thousands of dollars in debt! I don't know a single college graduate who doesn't regret their decision to pursue higher education. They all work at low-paying jobs that have nothing to do with the degree they payed so dearly for. Unless you know what you're doing, have lots of money, lots of connections (social capital) and a good contingency plan, attending college is one of the worst decisions you can make!
Feel better?
P.S. I want to make it clear that I'm not against attending college; it's just that most teens entering college have no frelling idea what they are getting themselves into! Go to college, but be smart about it. Choose a major with a plan as to how you are going to use it when you graduate. If possible, travel to Europe where university is free even to foreigners so you won't have to worry about debt.