Hacker Changed my email, but I regained access. How do i remove his email without waiting a month?

This morning about 2 hours ago, I was hacked. I lost access to my Microsoft account and struggled to get back in. Luckily, I was able to regain access through Microsoft support, yet I found an unrecognized email on my account, ******@fringmail.com. I attempted to remove it, yet it says I must wait 30 days for my security? He can just cancel this action if he logs back, re-change my password, and then I'm out again. How is it he was able to replace my email so quickly yet I have to wait a month? Is there anything I can do to get his email off of my account?