Was it because you werent comfortable with yourself and your social skills, or something else ?
Both. I've always been shy, anxious, and awkward in social situations (I have some pretty severe social anxiety problems lol). Then I hit highschool, and a lot of internal conflict over myself and my identity started up. Add that to the basic teenage social pressures, and it was a bad combination. I think it is for a lot of people.
I still have internal conflict and I still am anxious and awkward, but I find that the college environment is friendlier toward it. It's easier for me to work on getting past it here, than if I was back in highschool right now. There's a higher level of maturity, and you're less likely to run into the same people all the time, which takes off the pressure to not mess up somewhat.