I have friends but I still feel alone.?

[NotSoAwesome]

I have a "best friend" and we do all the usual stuff together. Once we were having a conversation about something nonsensical when out of the blue she said "I'm glad were such good friends even though we are in different friendship groups. Its great we don’t have to see each other every day to make friends" She meant it as a compliment as a good thing but to me it was a full on slap in the face. I was shocked and what was worse was that it was true, it felt like she was kicking me while I was down. I stared at her and started counting of my friendships in my head. There was "Anne", but she had better friends than me and I had no wish to talk to some of the people she hung out with. There was also "Jo" but I was just her go to for some intellectual release from all her friends who though Martin Luther king was the current president on the united states. I couldn't say that those were the only people I spoke too, but all I shared with the rest was some banter and a couple of laughs. They had better friends that they were closer to, and that got me thinking about my friendship with my "best friend", what did we have apart from the banter and a couple of years, we didn't tell each other secrets, we don’t talk feelings, we hardly make the effort to see each other outside school. There was my childhood friend "Karren" but we'd grown apart because of distance and our parents friendship growing apart as well. It felt like had no one, I wasn't unpopular and I could talk to almost anyone but people just don’t seem to get close to me. I felt so alone. I thought it was all in my head but when I stand outside school waiting for my sister the all can just bypass me look at me for a second and the walk out without even a smile of recognition which is probably nothing to them but is everything to me. By no means am I an introvert but I struggle with telling people what I really think or feel, I'm too eager to please and that I wrap friendships in fantasy's that only push people away. I felt too embarrassed to tell anyone even my parents because I love them to bits but they will either laugh at me or brush it off. I feel trapped and unable to express what it feels like drifting between friends and spending lunchtimes alone. I want a friend that I don’t have to pretend with, that doesn't have any expectations and I can just talk to. And I can't seem to find one and the feeling of loneliness is eating away at me?

1. These are their real names
2. i'm still in secondary school I know I have time to find someone i click with but the loneliness scares me and i makes me feel worthless because its my fault i have no one one to really talk to.
Thank you Claire! It helps to know things could change and I have taken what you said to heart.
Things might not be ideal now but I have hopes for the future.
Again, thank you for taking the time to respond.

NotSoAwesome

Ps. I'm from london