Managing personal Outlook.com account settings, security, and privacy
I'm sorry to hear about your problem. If your email address has been hacked, you should follow the instructions provided by Microsoft at this link:
https://support.microsoft.com/accounts-billing/manage/how-to-recover-a-hacked-or-compromised-microsoft-account
You can also use this form https://aka.ms/recovermyaccount, which will be sent to a team specializing in this type of problem. (Although it mentions Xbox, the form is also for Microsoft account recovery.)
Use this guide to help you fill it out: https://support.microsoft.com/account-billing/guidance-notes-for-the-microsoft-account-recovery-form-4dd8fef1-33d2-4fbe-9352-66127ab9b50e
You should receive a response by email. It may take up to 72 hours.
If you do not receive a response after this period, check your spam folder.