Why would this bitchh do this to me?

As your are reading, the person i think is acting bitchy to me is beccy and i honestly dont know why the hell she is doing this so heres what happened... Today ofter final bell, i go up to my one friend that i was talking about a pollyanna get together over christmas with and then "beccy" not caruing that i am there was like "omg i cant wait until tonight its gonna be soooooooo much fin." my friend "omg i know" the i was like for what.... then beccy says maybe ignoring what i say and more focused on what my friend had to say said... " ok so it is going to be you me, addy, beth, mary, and anne and cat if then can come." then i was like oh in a sad tone and walked away. Then i saw m friend and the rest of those girls i hang out with getting on beccy's bus so i call out to the frined i was talking to to say hi and she looked happy to say hi to me. I just don't know what to do anymore because whatever i try to do to get invited out more is a fail. i mean i want to do more but i am not invited and whenever i try to plan something, they cant make it. and also, i asked one of the girls who was going " what are you doing this weeked? and beth was like " oh nothing i am going to my gradeschool show and thats it." i didn't go to her gradeschool and she likely didn't want to make me feel bad about beccy leaving me out. I was really upset and now i am pissed at her for talking about it in FRONT OF MY FRIGGEN FACE! i would have rathar not known about it than to find out like that. So anyway, anything i try to get close to people is a fail and nothing seems to work. I just dont get it. I mean they are like best friends and i am looking like the lost pouppy. The only reason i got to their group is that my friend introduced me to them and said that she thinks i could be friends with them. I like my friend but it is getting really annnoying with beccy expecially. i just don't know what to do and i need some advice on how to get invited to thouse social gatherings ( i think of myself as a repellant to others because of how poorly i was treated in gradeschool and also i am not the person everyone wants to invite.... Beth is. ) and also, how can i become really tight with them? ( i am jealous because they got to know each other pretty well because of crew and i am gealous. i hate boats which is why i don't do it) So can you please help me?