Hello I fled my taxes with turbo tax on 04/07/2020. I just realized I filed 2018 taxes under 2019 so I need to amend them. I also need to filed 2017 & 2019 taxes.

If you e-filed a tax return through TurboTax this year, it was a 2019 tax return.  I will leave a link below with the instructions for amending a 2019 tax return.  I will also leave links for the 2018 and 2017 desktop software that you can use to file an original 2017 and 2018 tax return.  

All of these returns (2017, 2018, and the 2019 amendment) have to be mailed and processed manually.  The IRS is currently not processing paper-filed returns, so take your time and get them prepared and filed correctly.   

Amend a 2019 tax return

File a 2017 tax return

File a 2018 tax return

Mail the returns separately and be sure to sign them before you mail them.