In order to remove your old name/email address from Google after a name change, you may need to remove your old email from the 'Frequently Contacted' list in your Contacts, as well as the lists of others who may have contacted you prior to the name change.
How to Open and Access Gmail Contacts
-Select the Apps icon in the upper right.
-Select Contacts, which will open a new window with all your email addresses in it.
Select "Frequently Contacted" and then search [previous name and/or email address].
Click the three vertical dots and click More Actions and Choose 'Delete'.
You may elect to send an email to your frequent contacts to let them know to do the same.