Another person change my activation email id so please help me

Read this document if you think your Apple ID has been compromised. --> If you think your Apple Account has been compromised - Apple Support

For iOS 15 or earlier, if you want to see if anyone else has access to your device or accounts, click here --> Limit access to your iPhone or iPad - Apple Support

For iOS 16 or later see how Safety Check on iPhone works to keep you safe. How Safety Check on iPhone works to keep you safe - Apple Support

Use the information in this document to check your Apple ID device list to find where you're signed in --> Check your Apple Account device list to find where you’re signed in - Apple Support

Related materials:

Personal Safety User Guide

Personal Safety User Guide - Apple Support

> open the Table of Contents and review the articles

A document with general information about security and your Apple ID --> Security and your Apple Account - Apple Support

Contact Apple for help with Apple ID account security. This page provides country-specific Apple Support contact information ➞ Contact Apple for support and service - Apple Support