now heres how to default fix it.
1st check if you see a login on left upper nav bar.
2nd if you do press it and login with email and password.
3rd you're gonna be asked to reenter it.
If you were unhappy with your old name THIS is your chance to think of a new better one.

If you can't see a login link:
1st close all kdice and aplayr related windows and tabs.
2nd remove all or if you can aplayer relatet cookies
3rd see above.