First and foremost, I would not advise taking on more debt if you cannot afford your monthly minimums on your current debt. Think hard about what you can do to pay your bills every month without getting further in the hole.
Second, I would focus on paying at least the minimum on every credit card ON TIME for the next few months. The timeliness will affect you more than reducing the total balance.
Third, pay more than the minimums so you can improve your ratio. Ideally, pay off the credit cards entirely. Pay them off starting with the highest interest card first... but always pay the minimums for all cards (and on time!).
Lastly, the fastest way to improve your credit score is actually to find someone else who has a credit card with a long history and no late payments. Get them to add you as an authorized user. When their credit card reports an update to the credit bureaus it will be added to your credit as well and therefore improve your score. This does put the kind friend/family member at risk of having you use the credit so please respect their kindness and don't even let them give you the account number let alone the credit card.
Hope this helps! It took me 4 years to go from 690 to 816 so I study hard on how to keep it there. You can too!