Credit Score 714 Average is 665 nothing on credit but $190k student loans $5k credit limit how raise score?

I need to increase credit score. I've paid all negative credit off and had accounts deleted from credit report. Only thing on credit reports are 2 good cars 1 inactive good credit card and 2 active good credit cards with $2500 limit on each. Trying to get bar loan and don't have a co-signer.