Telegram Login Issue: Hacker Changed Email

I have been using Telegram on my Android phone, and yesterday my account was suddenly logged out. When I tried to log in again, the app showed an email address that does not belong to me, and I realized that another person is using my account and replying to messages as if they were me. My Telegram account is registered to my phone number +916200025*** and contains very important personal data and conversations. I am extremely worried that this information is being accessed and misused. I have not been able to perform any recovery steps from my side, because the system shows an email that is not mine and I cannot regain control of the account. I request urgent support to secure my account linked to this phone number, stop the unauthorized access immediately, and help me recover full control of my Telegram account as the rightful owner.