If you discover an issue with your Hotmail / Outlook.com / Yahoo account it is more than likely that your password has been compromised and you will have to change your password alongside of answering some questions about your account.
Your password should NOT be a word in the dictionary , the dogs name or similar.
This will hopefully enable you to get back in.
Your Hotmail / Outlook.com account is linked to your Microsoft account so the first thing to do is go through the steps of trying to change your password and or resetting your account by answering some questions about your account.
here are some links to assist:
Lastly when this is done , turn on 2 factor authentication , which means you will supply Microsoft with a mobile phone number so they can text you an access code.
Lastly choose a good password , not one out of the dictionary
if you are having issues with your Yahoo Account here is a link that should help.
Remember the same principles apply with passwords as above