If you log in to your MyO2 with the same log in as you posted here with and go to "Manage my details" you can change your email address there
https://accounts.o2.co.uk/?checkproduct=true
I have no affiliation whatsoever with O2 or any subsidiary companies. Comments posted are entirely of my own opinion.
This is not Customer Service so we are unable to help with account specific issues.Currently using:
Pixel 7a (O2 & Lyca), One Plus 6 (Sfr), iPhone 12 Pro Max (Vodafone)