unable to login

I was recently signed out of my hotmail account (another one, not this one) on all my devices. I also got calls from my relatives saying that they got some offensive emails from me. 

I tried logging in but it doesn't let me. I use the code sent to my phone, change my password. But when I press enter it says "oops, looks like someone else is using your account. Fill out this for or use a code sent to your alternate email". The alternate email I provided is no longer showing. It is a completely different email (that I can't view because it isn't visible except the first two alphabets). So I choose to fill out a form which is of no use because it says to fill out names of folders , sent emails, subject lines etc.

I don't use this email ID to send emails. I only use it for contacts and to subscribe to the stores I shop online at. I've tried filling to without these details but it doesn't help.

Can someone help me out?

The email ID in question is an @hotmail one.