How to add a W-2 to my return that was already submitted and accepted by the IRS?? The Turbo site that I am unable to amend via the Turbo Tax Online method until the end February... WTF :(

You cannot change or add anything on the return that you just e-filed, nor can you stop it.  It is too late, just like when you put an envelope in a US mailbox on the corner.

If you left out a W-2, or a dependent, or a 1099 etc…DO NOT change your return while it is pending.  The changes will go nowhere.

Now you have to wait until the IRS either rejects or accepts your return.  If your return is rejected, you will be able to go into your account and make the necessary changes to your tax return and re-submit your return.

 If the IRS accepts your return, however, then you have to wait longer until it has been fully processed and you have received your refund.  THEN you can prepare an amended tax return and mail it in. You have to be able to work from that return exactly the way it was when it was e-filed originally.  You will need to use a form called a 1040X. You cannot e-file an amended return.  They have to be mailed, and it takes about 4 months for the IRS to process an amended return.

 Meanwhile, DO NOT go in and start changing anything on your return in the system, or you will make a mess for yourself.  Sit tight and wait until you see what the IRS does with the return you just e-filed

The 1040X form that you will need will not be available until sometime in February.  You have three years from the filing deadline to amend a tax return to receive a refund, so you have time to wait a few weeks.  If the IRS just began to process your 2019 return, sending in an amended return would just confuse them and delay your refund for much longer--do you want to do that?