I accidentally filed my 2019 taxes as a possible dependent for someone else’s taxes. Which I absolutely am not. How can I change it?

[Critter-3]

If you successfully efiled the return you MUST WAIT until the original return has been fully processed and you have the original refund in your hands.   Only then can you amend the return. 

[xmasbaby0]

If you are amending to change your answer about being someone else's dependent in order to receive a stimulus check, the chances that you will get that check this year are very slim.  It is taking far longer than the normal four months for the IRS to process amended returns.  But if you are not someone's dependent for 2020, you will be able to get the stimulus money on your 2020 return that you file next year in 2021.