Managing personal Outlook.com account settings, security, and privacy
Sorry to hear you're having trouble.
First, if you haven't already done so I would like to recommend contacting your tenant and have them get in touch with their bank to dispute the rent. With luck the bank should be able to track and get it back for them.
As for your account issues, if you're able to please log in to https://account.microsoft.com and click on the Security tab to see if there was any unauthorized access or attempts. If you are unable to log in to the account then please try following the steps for the Sign In Helper as already suggested.
If there are further issues with accessing the account then please try completing the Account Recovery Form located here https://support.xbox.com/forms/recover-your-microsoft-account and then keep an eye on your email including the junk/spam folder for a response.