Just as a sidenote, all sororities have cliques to some extent.

Especially at large chapters. Plus, rush usually isn't the most stress-free time. I'm not saying join a group where you walk in and can practically hear the sisters hissing at each other

but don't let the fact that everyone isn't superduper best friends forever with each other put you off.
It sounds as though you made the right decision to stop rushing at this time though - if rushing as a sophomore is OK at your school then wait till next fall.