I quite recently changed both my mail adress any my password for my google account. When I now try to use my phone (any Google services) I get a screen: Verify that it's you (You were signed out of your Google Account. Sign in again to continue.) When I hit next a new screen comes up: Sign in with your Google Account Then there is a text field that says Email or phone. However in this very text field my old email that used to be associated to my account is written there. When I tap that field nothing happens. I cannot edit / clear that field I can only use my old email. When I hit "forgot email?" it leads to account recovery. If i hit next it says "Couldn't find your Google Account" (fair enough I changed my email...) What can I do, I tried restarting my phone, resetting Google Play and Google Play services in the app settings. I do not have any issues loging in with my computer, only smartphone wise that weird phenomenon occurs. Thanks in advance for any help!
You can remove the Google account from your phone by going to the settings > Accounts menu. There may be some differences in the name or location of the settings entry based on which company made your phone, but it should be something like that.
You can then add your new email/password combo to login to your modified Google account and everything should be fine. The associated accounts are not stored within the data of individual apps (like Play Store or YouTube) and that is why clearing their data does not make a difference.