@TurtleToo
One thing you might try, other than getting the Desktop program as @rjs suggested?
If you already have a copy of your Full TTX tax return, with all the worksheets as a PDF file, then you could print out just the TTX SS worksheet in that PDF. That worksheet contains all your current values, and you would manually add-in the income you apparently missed (lines 1-thru-4 or other lines) then go thru the calculations in any of the lines that follow to see what changes to see if the final result on line 20 approaches what the IRS thinks it should be.
_______________________
If you do not have the TTX SS worksheet, you'd have to get back into your tax return using the "Add a State" selection (you won't have to actually add one)...then go to the Print Center and download a NEW copy of your tax file as a PDF...BUT, you need to make the selection to include all the worksheets so that the TTX SS worksheet is included. Then get out of there....DO NOT actually change anything in your tax file. You don't want to mess anything up until such time as you decide you truly want to start an "amended" tax return. (If you do end up doing that, you have to start the actual amendment process before you make any changes)
____________*Answers are correct to the best of my knowledge when posted, but should not be considered to be legal or official tax advice.*
