If I change my email address I then have to change my AppleID. I have years of music and movie purchases on this AppleID across a few devices. Will I lose it all? I also have a monthly AppleMusic subscription recently started. Does this get wrecked too?
Changing the primary email address on an account should not affect any of its past purchases. To change it : Change your Apple ID - Apple Support
After changing it (preferably you'd log out everywhere before changing it, and back in with the updated version afterwards) : What to do after you change your Apple ID email address or password - Apple Support
Lose purchases after changing AppleID email address?
