Clearly, you have a situation that is best handled by getting a second credit card and use it for personal expenses. Do not link the new personal credit card to QuickBooks. 

Increasing "credit available" on your cards also will help with your borrowing capacity. Not just on the credit cards but also applying for business and personal loans. Just call the credit card company to increase your line of credit.

Your credit utilization ratio (also known as your debt-to-credit ratio or your balance-to-limit ratio) is one of the factors used to compute your credit score. A higher ratio means a lower credit score.

You can improve your credit score by increasing the amount you can borrow. I have five credit cards and use only two. My maximum borrowing is about $100,000 and I have less than $10,000 credit card debt at any one time. I pay all my bills 2 days early. My credit score is 840 because I pay bills on time, have multiple credit accounts,  high borrowing capacity, and a low amount of debt compared to what I could borrow.

I know this is not the topic however it is something to think about for the future as your business grows.