How can I stop being a loner?

You are not, you have hands, two of them. :)

If you're an introvert, i say put yourself out there and approach other people who seem shy and keep to themselves. Take a little initiative and try and interact with them, this is the hardest part -because- you're introverted, but introverts get along well with other introverts. On the other hand Introverts do NOT do well with extroverts since the way your mind works is entirely different. Extroverts thrive in group and public settings, where as Introverts do not. Here's a little something that might shed some light on being an introvert :) And may give some clues as to what you can do to make some friends.

http://www.youtube.com/watch?v=LxZ1fPr9FJg

I was always very shy when I was younger too. In school you are lucky because there are groups and clubs that you can get involved with that will help you to break the ice with others with common interests as yourself.

You will have to put your shy tendencies in check though and smile and say hi when you encounter people that you have met before. They will start to say hi back, then a couple more encounters, and you guys may start having a conversation with each other.

Just be friendly but not pushy and you will start to meet other people. The websites I am listing below may help. http://www.zujava.com/lonely-lonesome-alone This next one I started to write in a humorous light and then I realized as I did research that I am an introvert as well (and a perfectly happy one I might add especially now knowing I am normal lol). http://www.zujava.com/social-anxiety-dating-phobia

Good luck in your quest.

You need to start hanging out where there are people or joining some clubs or participating in a league of some sort. Honestly its not so bad being a loner most people arent worth your time. You might be better off with a dog or cat.