IM DEPRESEED AND AHVE NOO LIFE..PLEASE HELP!?

im a 15 year old girl in highschool. i have 3 close friends. and other freinds thta talk to in school. i text my freind lizzy every single day, we havnt gone a day without texting for a year.BUT I NEVER HANG OUT WITH THEM...they never invite me over and i never invite them ver..i would but i dont know what we would do? why dont they invite me over? my best freind sara...doesnt really act like a best friend..but we have to be bestfreinds because everyone already has a bestfriend...and its complicated but we just have to be bestfriends, i never text hr of hang out with her she just drives me to and from school...to tell you the truth i hate her...she always invites lizzy over..but not me..and i never ell my friends secrets like a normal teennager does..we rarely ever gossip! we talk abou other things, we dont talk about guys with me or life or gossip about school, but they talk about that stuff to other people? and whenever they hang out with guys they dontt invite me to? ive texted one guy in my whole life..ik pathetic...! what can i do to to get them to invite me over??? what can i do when i invite them over? how can i get them to tell me more secrets and gossip? please help ive been so board and depressed...