Sorry to hear that you're having this kind of trouble. I come from a small chapter too, but we haven't experienced these kinds of issues.
As far as the dinner thing, it sounds like a miscommunication; we've had communication issues in the past and had a communication session to help sisters resolve those issues(played telephone to relate how much something can be distorted, did the badge-drop exercise, set communication guidelines, and offered a beef-box session if it was needed).
**For the badge exercise, it was surprising how fast it dropped. [Put a badge or new member pin or both on a piece of fabric large enough for all members to grab with one hand. We found it effective to use the banner. Take a list of behaviors that are detrimental to sisterhood (that were previously prepared), and tell everyone to close her eyes. The person reading the list turns around so it can remain anonymous. If a sister has done one of the things on the list, she drops her hand, or a finger if you want to make it last longer. ] The fallen badge is a good visual representation of how quickly a chapter can crumble if it's not united. **
For officer elections, make sure that your slate committee next year is completely close-lipped about who's interested in what. If sisters want to talk amongst themselves about what they wrote, try to keep it to a minimum.
Have you had your Consultant visit yet? She may have some great ideas for you!! Ask about communication programs, e-mail her if she's already visited you.
Don't let a few sisters who want to act like drama queens distort your view of sisterhood. They will cool-off. Remember why you joined Sigma in the first place, and keep in mind the values and reasons why our sorority is so special to you. Hope things get better!!
Sigma Love and Mine,
Laura
ps - are you from Zeta Theta? If so, your consultant is Jennifer, and she's super nice and very helpful!!