Schedule B has an entry "accrued interest paid" that is the exact amount of money that I entered as interest received. Where did this come from?

If you are reporting Interest income on an instrument like a bond that had accrued interest at the time you purchased, then would reduce your interest income by the accrued interest at your purchase date. Report the full amount of the interest, and then enter the Accrued Interest paid as an adjustment to reduce it.

When you buy bonds between interest payment dates and pay accrued interest to the seller, this interest is taxable to the seller. If you received a Form 1099 for interest as a purchaser of a bond with accrued interest, identify the amount to be subtracted as “Accrued Interest.”

If you have questions about the amount of the accrued interest, contact the payer of the Form 1099-INT.

You may have entered the accrued interest adjustment in the 1099-INT section of TurboTax. 

Follow these steps to make an adjustment for the accrued interest paid on your taxable bonds:

1. Select Federal Taxes
2. Under Wages & Income select Interest on 1099-INT
3. Enter your 1099-INT information, select Continue
4. Select I need to adjust the taxable amount, select Continue
5. Enter the accrued interest paid in the Adjustment box
6. Select the Reason for Adjustment as My accrued interest is included in this Form 1099-INT

 See here for more information from the IRS on this topic. See this thread for another discussion of this topic.