Honestly, prosper.com or a friend/relative (wich is a BAD idea) are the only solutions, if your bank can't do it.
The best solution, short term, is to earn more - or spend less - money. Otherwise, you'll be paying twice the amount for your loan (ex : 6,500$ loan @ 11.75%/y = 60 months X 155$ = 9,300$ - and that's a GREAT rate, with co-signer).
So, do everything to control the costs, and/or to earn more money : rent a room, sell your car, or any assets that you can live without.
On the top of that, find a way to put some money in a savings account, even if it's 20$/month !
After a year, when your credit score will increase, you'll be able to get a loan or consolidationn loan at a better rate.
Good luck !