Hi Alison,
Based on your description, it seems that your email account is suddenly been locked out. Maybe somebody is trying to access your account without your knowledge. I understand the importance of recovering your account as soon as possible.
If you are unable to access your account, it is possible that Microsoft has detected suspicious activity on your account and has temporarily locked it for security reasons. In this case, you will need to go through the account recovery process to regain access to your account.
To better understand the situation, I would like to ask some questions, such as:
- What email domain are you using? (this time please provide the email domain only e.g. @outlook.com, @hotmail.com, @live.com, etc.
- What error message are you getting when you login your account? please provide us a screenshot of the error
- Are you still using the phone number & email address you used as security information when you created this account?
To regain access to your account, you can try resetting your password by following the steps provided on the Outlook.com sign-in page - Reset a forgotten Microsoft account password - Microsoft Support. Please take some time following the corresponding steps on the article
I wish you well and good luck!
Sincerely,
Leonardo_Y