Having been in a somewhat similar situation once myself (my loan and grant funds were held up due to a paperwork glitch once, way back when - I found out during the 1st week of classes that my tuition hadn't been paid and my classes had been dumped) the best advice I can offer is to go in and talk directly to someone who can ACTUALLY fix things for you (the school comptroller, for example). That's what worked for me. If you just talk to some department clerk, you'll usually be told "no." Talk to a bigwig, and ask them for a more reasonable payment plan. 🙂
On the subject of financial aid, I know that for federal aid (Stafford Loans, Pell Grants, etc.), your parents' income counts against you REGARDLESS of wether you live with them or not, until you turn 24. There ARE exceptions, of course, but only if you've been orphaned, were ever a ward of the state, served in the armed forces, etc. Private aid and aid from your school may have different rules, though...
Good luck!