I encrypted my iphone backups, and forgot the pw - i know..

Is there a way i can delete all the backups, so that i can start backing up from a fresh, this time with out encryption ?

At the moment im stuck in this loop (bellow) - its not worth be backing up my phone becuase if its lost i wont be able to access the backup any way

Ive tried going writing down a list of all possibility and going through entering each one, but to no avail..