I just received a summons (AZ) for a debt of a business I used to own. I had made several payments on the debt and the amount I am being sued for is almost the whole amount of the loan plus attorneys fees and interest. I cannot pay this debt now and I don't believe the amount is correct. Do I have any recourse now?

Make sure you have all receipts.
They will go after as much as they think they possibly can and then the Judge will determine what you pay. Often they will just go with the principle and not the fees and interests. At least that is what has happened with everybody I know.

Its not unusual for interest and attorney fees to greatly increase the amount of a debt.

You are entitled to an accounting of the debt. But inability to pay is not a defense.