>>1 stay a kind person. That is incredibly important. Those 'friends' don't deserve you either.
Now I can relate, in middle school I had a similar situation, I tried so hard to fit in and have friends but for whatever reason, people didn't like me, I've been treated as an outsider for a long time. I became introverted and shy.
One day in junior high, I became friends with a girl that I never talked to by being kind and inviting her to my house to ditch a photography class (skipping class is bad! Don't mind me!). She got me into anime and we're still best friends. After a lot of anime series my inner fangirl needed to fangirl so I started discussing anime on facebook pages and soon after I made a lot of internet friends, the chatting and discussing made me more confident and now I can confidently talk to others, I'm crappy at speaking but I try...
My advice to you is to start out small. Confidence is a skill so it's something that needs to be worked on until you're good at it. Take a deep breath and say something to the person next to you, talk about the weather or coffee or something! The worst thing that they can do to you is reject you. Rejection hurts but you can't let it, tell yourself "I'm a good person, anyone would be lucky to be my friend, that person doesn't deserve me." and move on.
It's easier to chat with people of the internet, since if they reject you all you have to do is click the exit button or find someone else to talk to. Don't psych yourself out and keep trying! Just be careful with the internet and strangers.
I hope that this helps :3