Your loan balances also affect your credit score in a similar way. The credit score calculation compares your loan current loan balance to the original loan amount. The closer your loan balances are to the original amount you borrowed, the more it hurts your credit score. Focus first on paying down credit card balances because they have more impact on your credit score.
This is easier said than done, but reducing the amount that you owe is going to be a far more satisfying achievement than improving your credit score. The first thing you need to do is stop using your credit cards. Use your credit report to make a list of all of your accounts and then go online or check recent statements to determine how much you owe on each account and what interest rate they are charging you. Come up with a payment plan that puts most of your available budget for debt payments towards the highest interest cards first, while maintaining minimum payments on your other accounts.