Try and install gnome if you don’t want to switch from it because of Unity.
Here are the steps:
1. Open shell and run
sudo apt-get install gnome-shell
2. Once the installation is complete, reboot.
3. Switch to the desired shell from the login window.
Note: If you encounter errors or failures during previous step for any dependent packages then you may want to update the packages by running
sudo apt-get -f install