All your income information must be included on ONE tax return. If you file early and then get more information, you have to prepare an amended return -- this is a new return that has all your information, old and new, and a summary page describing the changes.
If you filed one return. then changed the information without amending, you erased the first information plus you never filed your second tax return.
What you need to do now is BUY a copy of Turbotax foe 2016 to install on your own computer. You can't use the free amend-only version. Look for it on the main turbotax page at the bottom under "past year products."
First, you will re-create the original return exactly the way you filed it. If you aren't sure what you filed, you can request a transcript from the IRS. https://www.irs.gov/Individuals/Get-Transcript
When this return is finished, "file" it by saying that you will print and file by mail, then print a copy. This marks the return as filed. Quit the program, restart, and then under "some things you can do" click "Amend a return." Prepare the amended return that adds your second W-2. It will change your refund and probably result in you having to pay back some tax. Print the amended return (all your forms plus a form 1040X cover page), sign it and mail it to the IRS. You should expect a bill later for late fees and interest, if you actually owe some tax back.
If you don't file an amended return, you should expect to receive an IRS notice telling you that you missed a W-2 and assessing tax due plus penalties and interest. (However, if adding the second W-2 results in a second refund, the IRS won't notify you or pay you unless you file the amended return.)
You may want the help of a professional.
Amend https://ttlc.intuit.com/replies/3288565
