I didn't drink when I was in college, but I did enjoy going to the parties. Yep, you can have a blast at them totally sober.
I love music and dancing, so getta outta my way if there's a dance floor.
None of my sisters ever gave me a hard time about being one of the few who didn't drink and hopefully yours don't either. I did tend to gravitate towards the girls who drank very little and became closer to them (they are there--if your chapter is big, it may just take a little time finding them). The chapters at my school weren't very large at the time, but did find girls I had things in common with. It will come. The suggestions others have mentioned like doing study sessions together, etc are a good way to bond outside of a party atmosphere. What about going to the movies together? My close circle used to go to them all the time.