Advice on improving credit rating whilst studying

charger1008

I have just been refused a career loan from Barclays (i bank with natwest) due to my credit scoring. I only ever got one loan out (student loan) which when i can i pay off (as the legal terms state above 21k etc) I currently live in my overdraft and don't earn enough to live off, pay rent and pay off overdraft. Banks suggest a loan? but then thats more to pay off eventually plus it won't immediately help with the fact i can't study now. I need some guidance or advice (aside from bank advice) into how i can get out of this situation to improve my credit scoring and bring myself back up to date.

any advice at this moment. feel a bit stuck!