If you created a buyer account with the incorrect email address, fear not, you can change the email address to the correct one!
First login to your buyer account using the email you used to create the account. Then click on Account Settings.
Add a secondary email address (the one that you want to use) and click Add and Save Changes.
Check your email (the secondary email address you just entered) for a verification email to confirm the new email address. Click the Verify Address button.
You will be taken back to your Account Settings. Here you can make the secondary email address the primary address. Click Save Changes.
Then, delete the secondary email address.