Very sorry for your loss. We have some guesswork to do here, though. Was John your spouse? And he passed away in 2022? For the year that he passed, 2022, you could file a joint return. After that, unless you have a qualified dependent child, you will need to file as Single. It is better to start your own new account with a new user ID, because -- as you see-- using an old account that was used for past joint return will still keep bringing up embedded information for the spouse.
https://ttlc.intuit.com/community/using-turbotax/help/how-do-i-start-another-return-in-turbotax-online/00/25596