How do I changed the my email address of my account on my Iphone

You can change the existing email address to a new one on the same account. But if you have created a new Apple ID switching to it will result in the loss of all your purchased music and apps, because purchases are associated with whatever account they were purchased with forever.

To keep the same account and change the email for it see→Change your Apple ID - Apple Support

To switch your phone to a new Apple ID account you must first log out of the current Apple ID, then log in with the new one:

• If you don’t have a recent backup, create one on your computer or in iCloud (just for security, you probably won’t need it)→How to back up your iPhone, iPad, and iPod touch - Apple Support
• Go to Settings/[apple ID name] and tap Sign Out
• If you sync to iCloud you will be asked if you want to keep the content that syncs; say yes to each item
• Tap to create a new Apple ID
• If you sync to iCloud, go to Settings/Apple ID name]/iCloud and turn on the switches for items you want to sync.
• Log in to the same email accounts you had on the shared Apple ID if they have logged out (they probably did not, unless one of them was an iCloud email address)

Contacts, Calendars, Notes, and Reminders sync to email accounts, so if you are logged in you will still have all of them. You will also still have all photos.