The very simple answer is that it is over and done with, you are stuck with a result, and there is nothing you can do about it.
You must report the excess deferral on your 2019 tax return. Because the deferrals were reported on your W-2s, this should already have been done for you by your tax preparer or by the software that you used in 2019. Check to see if the line 1 taxable wages are equal to the total of your two box ones from your W-2s, or is more than your box 1 total by the amount of the excess.
then, there is nothing else you could or can or should you do. You will pay income tax on the total amount of any withdrawals you make. If you make withdrawals before age 59 1/2, or before age 55 if you’ve separated from service, you will also pay a 10% penalty. There are no ongoing penalties (you may have been reading about a Roth IRA) and there is no way to make a corrective distribution.
