Yes, you need to report the total value of your IRA, because based on your comments you did make nondeductible contributions. To determine what your nondeductible contributions are in total, you will need Form 8606. Form 8606 should have been filed with your tax return each year when you made after-tax contributions. TurboTax uses this information to figure out the taxable amount of your distribution.
Form 5498 is just an informational form from your brokerage firm that shows what your contributions were. You will need the year-end statement from all your accounts to determine the total value of all IRAs on 12/31. If you do not have this information contact your brokerage.
If you have any other questions once you get all your information, feel free to reach back.
