I'm sorry to hear that you're experiencing this issue. I'm happy to help.
Many Microsoft users are experiencing the same issue, and this is likely a phishing scam email.
Official Microsoft account security notifications come from addresses ending with:
@accountprotection.microsoft.com
Avoid clicking any links or downloading attachments from the email.
If you didn’t request any changes and the email is not from an official Microsoft address, it’s safest to ignore it or report it as phishing.