Using Classic Outlook on Windows for personal email, calendar, and contact management
That indicates your account was hacked and stolen - they changed the address so your can't get it back. Sorry.
See this article - https://support.microsoft.com/en-US/accounts-billing/manage/my-username-and-password-have-stopped-working - for the steps you need to recover it.
If you get it back, you need to enable 2FA on it (with at least 2 methods of recovery).