More details may be needed but I don't think you do. You can only deduct a debt if you previously reported the income. If you did a job for someone and didn't get paid, then you already deducted your expenses. Now you have no offsetting income, so by simply not having the income you aren't taxed on it. You can't deduct the loss again.
If you made a loan using after-tax dollars that may be deductible.
