I loaned myself money from a credit card by charging it in my business account. It is registered as income. Do I still have to pay taxes on that amount?

"Do I still have to pay taxes on that amount?"

It is not entirely clear what you actually did, but loans are generally not considered "income". Thus, I believe you made an entry error, which you can easily reverse.

No, that is not income. The entry should be to "Loan Payable" instead of "Income."