As you are required to report ALL income, you need to include all W-2s in your tax return.
As you have already filed, you have to wait to see if your return is rejected or accepted.
If your return is rejected by the IRS, you can add the additional W-2 and correct other errors, then re-file your return.
If your return is accepted, you'll need to amend your return. Please note that the amended form will not be ready before mid-February.
To amend your return, please follow the instructions in this TurboTax Help topic.