Are they making you pay your own tuition, books, room, and board, too?? If so, make sure your financial aid package takes that into account.
For your sorority dues, try to work out a payment plan with your treasurer - that way you won't have to write a big check all at once.
As for a job, I graded problem sets for a couple of semesters for some extra $. Is this an option for you? Obviously it wouldn't help you right now...
Oh, if your parents have made you totally financially independent, don't let them claim you as a dependent on their tax return - you probably need the deduction more than they do!