Ok so I managed to upgrade to Debian 11 following this article, and now cat /etc/debian_version gives me 11.0. Now I have many dependancy issues:
I tried out sudo apt --fix-broken install, but it didn't help
I also got this message halfway through sudo apt --fix-broken install.
┌──────────────────────────────────────────┤ Configuring libpam-modules ├───────────────────────────────────────────┐│ The pam_tally and pam_tally2 modules have been removed from PAM. You are using one of these modules in your PAM ││ configuration in /etc/pam.d. You must remove the uses of these modules before PAM can be upgraded; including ││ these modules in your PAM configuration after the upgrade will stop users from being able to log into the │