If you are able to change the password, it means you still can access your account.
If that's the case, you must change the password again AND add TWO-STEP VERIFICATION to your Microsoft account using an Authenticator App installed in your phone.
Follow this link:
You must change your email's password as well and add Turn on 2-Step Verification to your email account as well.
Assuming it is Gmail account this is the link:
https://support.google.com/authorizedbuyers/answer/2690010?hl=en
https://support.google.com/accounts/answer/185839?hl=en&co=GENIE.Platform%3DDesktop