If you start your new return in exactly the same account with the same user ID that you used for 2018 and you choose to transfer your 2018 data in to the 2019 return before you enter any other data yourself, it would do just what you are complaining it did not do. It sounds like you did not transfer 2018 to 2019.
How to transfer last year’s return? https://ttlc.intuit.com/questions/1900883
Many people have multiple TT accounts and forget how to access them. Log out of the account you are in now.
Account recovery
https://myturbotax.intuit.com/account-recovery/
https://ttlc.intuit.com/questions/1901535-forgot-your-turbotax-online-user-id-or-password
Or did you use the desktop version of TurboTax? If so, the files are on your own hard drive or any backup device you used like a flash drive.
https://ttlc.intuit.com/questions/1901486-how-many-turbotax-accounts-do-i-have
https://ttlc.intuit.com/questions/1901535
https://ttlc.intuit.com/questions/1901659-find-your-tax-data-file-in-mac
https://ttlc.intuit.com/questions/1900721-find-your-tax-data-file-tax-file-in-windows
To get a copy of your previously filed returns prepared with online TurboTax https://ttlc.intuit.com/questions/1900748-how-do-i-get-a-copy-of-a-return-i-filed-in-turbotax-online
https://ttlc.intuit.com/questions/1900748-how-do-i-get-a-copy-of-a-return-i-filed-this-year-in-turbo...
**Disclaimer: Every effort has been made to offer the most correct information possible. The poster disclaims any legal responsibility for the accuracy of the information that is contained in this post.**
