There are two things you need to do... First, go to your settings>Accounts>Google and make sure sync is turned on for your Google account (especially for your contacts) and tap sync. Secondly open your phonebook (or contacts) on your phone and go to settings, from there go to display options and make sure that contacts from your e-mail id are allowed to be displayed in your phonebook.
If all else fails, you can simply log onto your computer, go to google, make a backup of your contacts from your e-mail account (it is in the manage contacts option in your e-mail id) and put that file onto your phone and import it in but that's the hard method obviously