I forbid you to quit!

At least give it one more shot. Maybe this is just one of those times when everyone is busy and stressed out, so they take it out on each other. I know you have your work cut out for you especially with the situation on your campus, but just think how great it would be if you actually made this work? If you try again and it *still* doesn't get off the ground, then you can say you gave it a good honest effort and leave it at that.
It sounds like your dear old pal Betty needs to wake up. Honestly--wouldn't it be better to be Greek yourself and be a part of a sisterhood rather than tagging along with your boyfriend's fraternity all the time? Just remember, though, that this sort of petty stuff happens in almost every sorority (well, at least every chapter I've come into contact with), and it's almost a given. It can be sorted out in the majority of cases. But I don't think I'd be giving Betty a bid anytime soon if I were you all...
Good luck to you! If you need anything, just holler.