Issues such as this can be caused if your phone is full or almost full, so when you get back up and running have a clear out of any old photos, apps and videos etc that you don't need anymore.
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)