I was a shy kid in high school, then got really bad in my early college years. I was so painfully shy that I couldn't look at people when I talked to them. It got so bad that one day I decided this "fear of people" I had developed wasn't healthy - and decided to take steps to get over the "fear" part of my shyness. Being shy/a loner isn't a bad thing unless you begin developing a fear keeping you from attempting to connect to other humans.
Where I started was I took a job at a McDonald's - not just for the money, but that if forced me to look up and say "Hi. Welcome to McDonald's. May I take your order?" to another human being...repeatedly. It was almost self-prescribed therapy to force me to deal with and get over the fear portion I had developed.
My best friend from college met me a year later - she was on the same dorm room floor with me and noticed we were in the same class together. One day she followed right behind me from class, back to the dorm, right up to my room - so when I turned to close the door, she said "Hi" and introduced herself. I had no idea she was there (that's how introverted ... and oblivious I was back then). She was great for me - we became roommates the rest of college. Then she got me involve with the campus ballroom dance club.
The Ballroom club did wonders in opening me up. I really took well to that, and eventually became a teacher. Through that club, I developed a more outgoing personality - one I could "put on" when I was in uncomfortable situations. It was still me, but a personality I felt comfortable with to "fake it" until I no longer felt the shyness.
Now - I still get the occasional "panic" feeling when I'm in some new situation, but I've developed so many ways to get past that gut reaction, it hardly phases me anymore. I still feel it inside, but I don't let it stop me. Too much to do an see in this life.
