Please help!! What do I do?

[Grr]

Continue to try to talk face-to-face with this girl that got inbetween you two. It will even be better if you 3 were in the same room together so you can all work out your differences. But anyway when you sit down and talk to this girl, make sure she realizes everything that's bothering you and have her feel bad for excluding you out on certain activities. If she continues to avoid confrontation, you have to constantly annoy and nag her until she agrees. Doing something like this through text or facebook proves to be insincere and not serious, you need to explain this to her.