Last year I paid 38% when my tax bracket was 12%. Same thing again this year. Can I use the overpayment from last year and apply it to this year?

Did you get a refund from last year or did you choose to apply it to this year?

If you chose to not get a refund and apply it to this years taxes then yes, you can apply it to this years taxes. You would do this by selecting the following:

1. Federal
2. Deductions and Credits
3. Estimates and Other Taxes Paid
4. Federal Estimated Taxes
5. Enter the date as the date you filed last year and the amount you did not get.  If you do not remember the exact amount, you can find this on your IRS account. 

If you used the same account in TurboTax, be sure that it did not carry the amount over the amount prior to making that entry. You should see this on the summary page.