I tried to add it, and it changed my return amount, but when I go back to the homepage, it changes back to the original amount from when I filed in January. I just want to make everything right so this isn't stressing me out.
No you can’t do that. You need to file an Amended 1040X return to add or change anything. So first make sure to take out the W2 and put your return back to the way it was when you filed it. Then wait until the IRS is done processing your return and you get the first refund. Then you can amend when the amended form is ready.
When it’s time to amend you start the amend process first then add the new W2.
How to Amend this year
No you can’t do that. You need to file an Amended 1040X return to add or change anything. So first make sure to take out the W2 and put your return back to the way it was when you filed it. Then wait until the IRS is done processing your return and you get the first refund. Then you can amend when the amended form is ready.
When it’s time to amend you start the amend process first then add the new W2.
How to Amend this year