My iphone notes don't sync and the ACCOUNTS button disappeared in the blink of an eye while no one was using the phone

My notes from other accounts disappeared AND the accounts button in my notes app disappeared. What do you do when the notes AND the accounts button in the notes app both disappeared suddenly one afternoon. One minute they were all there, including the ability to go to the various account sin the notes app, and the next the ACCOUNTS button is gone and are half my notes. How do I get that all back?

They were all there at 2:30pm when my calendars synced but were gone by 3pm and I had not touched my phone (nor did anyone else) in between.

Please help me get the accounts selection back in my notes app and get my icloud notes to sync up again