How to be outgoing and boost my self esteem?

[couch :3]

when i was in 1st grade, my family was really poor. yet they wanted me to get a good education so they sent me to a really classy private school where literary everyone had a big house and a pool in their backyard and could go on trips for vacation, when I couldnt get any of that. I had no friends, everyone there made me feel like an outcast, i was always the last one picked and first one picked on. That really lowered my self esteem. Once I became so desperate to make friends, I made up a story about having a cool rich best friend who did all these cool things, but when everyone found out it was a lie, they hated me even more. After that I've always been really shy and awkward. Now im in high school, my family isnt poor, and I feel like I'm equal, like this is where I belong. But I get really shy when it comes to talking to people who are more popular or cooler, or have more friends then me. And I really wish I could be more open, because I know I could get along with these people if only I became felt comfortable around them.