I am starting to feel so jaded about "sisterhood."

[TEAtime]

I didn't imagine that your sole purpose for joining a sorority was to be able to couch surf when necessary; snark doesn't always carry over so well on these here interwebs :-/

Try not to beat yourself up about it; i.e., don't feel awful. Talk to your sisters. Things may be awkward, but it is what it is (don't fall into the introvert trap of letting your thoughts consume you). I'm not saying this is what you should do, but in your shoes I might book a room, then personally reach out to sisters I know will be in town and offer to help them move into their summer spots. Or, I'd see if anyone's available to hang out one evening before you go home. Things will work out.