Here is the story:
I was on Ubuntu 18.04 with the default configuration and display manager. Then it froze so I pulled the plug by holding down the power button.
After that it would boot normally and the log in screen showed up, I entered my credentials and then the screen went blank.
I searched for a solution. And I fiddled around with many commands and I switched display managers, I tried lightdm but I didn't like it so I switched to gdm3 which supposedly was the default and it worked but after I did sudo reboot it went straight to the boot process and it shows lubuntu in blue, how do I switch it back because now it's super slow User Interface.
Please help, thanx!