I pay my bills on time now and have been for years, but my credit score is toast because of a collection write off I had about 5 years ago and a maxed out home equity line of credit. It's kind of scary to put all my extra money into paying down my line instead of putting aside anything into savings. I really can only do one or the other. My car note interest rate is astronomical with no way to refinance because of the FICO and my house mortgage is underwater so I can't take advantage of low rates these days. I guess I'll just put half on debt and half in savings and do another credit report in 6 months.
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.