my son and i used to share an apple id but now he has set up his own. My apple id has my email address, phone and devices associated with it but my device still shows my son's contact photo in the apple id settings so it thinks I'm him

Howdy,

It sounds like this is what you want to do, Change your Apple ID email, password, or profile picture

Change your Apple ID picture

Your picture appears on your iCloud.com homepage and in Settings on your iPhone, iPad, or iPod touch, in System Preferences on your Mac, and in the iCloud for Windows app on your Windows computer. If you joined Family Sharing, others in the family can see your Apple ID picture in their list of family members.

Do one of the following:

• On iCloud.com: Go to Account Settings, click the picture next to your name, then drag an image file onto the picture. Or, click Choose Photo, then follow the onscreen instructions.
• On your Mac: Choose Apple menu  > System Preferences, then do one of the following:
  • macOS 10.15 or later: Click Apple ID, click the picture above your name, then select a new picture.
  • macOS 10.14 or earlier: Click iCloud, click the picture above your name, then select a new picture.
• On your iPhone, iPad, or iPod touch: Go to Settings > [your name], tap the picture above your name, then follow the onscreen instructions.

ivan