Email app disappeared and now I can't access email
Try this.

Swipe down from the very top of your home screen. Type "mail" into the search field at the top of the screen. if the mail.app does not show up you may have accidentally deleted it. This is also an easy fix.

Go into the App Store, tap on search and type "mail app" look for the familiar icon and make sure the developer is "Apple." You can then "re-install the app like you would any other. There will be no charge to do this. This is merely the way Apple decided how to put back icons that you have deleted.