My best friend's other friend really doesn't like me.?

I recently moved away from a country I'd been living in for a long time. My very best friend for all those years(and love interest) is still in touch with me, but she doesn't log on to anything but Skype, so I talk to her there.

Anyway, I never talked to her over the internet before I moved. It turns out that she has this group of online friends of which she practically worships one(let's call her S). Unfortunately, that person she worships hates me for some unknown reason; in short, she does all sorts of things to hurt me and make me feel excluded and jealous.

I'd just like to quit this whole 'group' thing, but my best friend will only talk to me in a Skype group with these people. Of course, she would agree to talking to me outside of it (she's a good friend), but she talks a lot in the group chat and barely says a word on personal chat.

I don't want S to hurt me anymore, (and ignoring all the things she does is very difficult for me, as I'm quite affected by these things), but I want to talk to my best friend as much as possible. What should I do?