How can a grad student with bad credit, no cosigner, and all federal funds exhausted, get a student loan?

Help! Help! Help! I am currently a grad student who needs more student loans. I don't have good credit, and getting a co- signer is NOT an option. The federal loans will not cover all expenses. What do I do? I'm trying to get private loans, but of course, they are credit based, or I need a co-signer. My education should not suffer just because my credit is not good!