kkhosa; Hi ! Welcome to the forum .
Maybe you have lost the authority to access your home directory in the GUI environment; to check:
1. At the login screen, press Ctrl+Alt+F1 to get to the console.
2. Log in there.
3. Check if ".ICEauthority" is owned by you:
4. If it isn't (but possibly by root), change it to you:
ls -al .ICEauthority
where "USERNAME" is your actual user name.
sudo chown USERNAME:USERNAME .ICEauthority
5. Switch back to the login screen by pressing Ctrl+Alt+F7 or F8
6. Try again to log in.
7. Repeat this procedure for the file ".Xauthority".
If it worked, see here about a possible cause:
just try'n to help