How do i get my friends to not ignore me?

I'm in middle school, and I have a group of friends that have about ten people in it. And we also hae some other people from other schools. So that makes our group hae 20 or so people. ALL of them go to the mall and stuff every single weekend and I'm never invited to them. The only times they wanted me to come was the holloween and christmas party and once for my best friends birthday party. They openly talk aout plans in front of me and they all steal looks at me because they know haven't been invited. Also, on facebook, when soe of my friends tag our group with those picture with a bunch of personalities, I'm never in any of them even if I fit one of them perfectly. There was also one tag that said " if your tagged, we lovve you" ewhere everyone in our grroup including some people that neer hang out with them. I wasn't in it. I feel like such a loser who just taggs along with everybody. When they all walk in a line down the hall, the make sure I'm on the fvery edge or not in it at all. I try to pretend it doesn't bother me and id raather be alone but its really too much now. If I called my best friend in thatgroup, shed think it was really important because we usually just text eachother while her other friends would be abke to talk over the phone for hours about nothing. They're all so cclose, and I not. What are some things I can do to get my friends to include me and actually notice how great I am. Whatever, I just need some help with this. Please don't say those aren't my real friends andi should find others because I know id never like another group like this even if they are ignoreibg mre,, these are my typevof people. Thanks...