X2go has taken over my computer

I needed to login to the uni’s server to test an assignment and they gave us instructions to use x2go. So I’ve installed it from the repo. During the install process it asked what I wanted my default manager to be gdm3 or x2gothinclient. Thinking this was the default remote desktop app I selected x2go.
After restarting my computer I can decrypt my drive, but then it loads the x2go login page!
I cannot even log into my uni server (as the two options are examples) and I don’t know how to get a local terminal to switch the display manager!!

Can anyone help me get my computer back?

I tried searching the webs but cannot find anything. Why is that even an option?!?!?

After writting this I thought about seeing if I can get into recovery mode, and that fixed it.

Turn the computer on and hit Esc for the BIOS menu to pop up.
Options -->
Boot Options -->
Show OS boot menu
Select the latest recovery mode

i.e. PureOS_GNU/Linux,_with_Linux+5.10.0-8-amd64(recovery_mode)_[/vmlinuz=5.1…

Hit enter 2 times until the terminal asks for your decryption key.
Now you are logged in as the root user.
dpkg-reconfigure gdm3
Then on the blue screen select gdm3. Then reboot.

Everything should be back to normal.

Can we get apt to not ask to switch display managers when installing?
If a person wants to switch to x2go or Plasma. AFTER installing they should then type in a command to switch, NOT during the install of the package.
When I install Firefox it does not ask me if I want to make it the default app, why should display managers be allowed to ask?