How to revert unity and remove gnome desktop?
If GUI is troubling you, login through CLI(Ctrl+Alt+F1)
Check if ppa-purge package is installed or not.
Run
dpkg -l | grep ppa-purge
If it returns the value, ppa-purge is installed. If not, install it as follows;
sudo apt-get install ppa-purge
After that run the following commands;
sudo ppa-purge ppa:gnome3-team/gnome3-next
sudo ppa-purge ppa:gnome3-team/gnome3-staging
sudo ppa-purge ppa:gnome3-team/gnome3
sudo apt-get remove gnome-shell ubuntu-gnome-desktop
Reboot system and login through Unity.