I got my xbox account hacked and they changed my mail and password... how do i get it back?

My account from xbox wich uses the same mail I'm using to post this got hacked and the hacker changed the mail and password from that account. So now I can't get in my account because it says It's someone elses and it ask me for a code from that mail and when I try to sign in whit my mail it takes me to the customization menu like it was a new account and when I open the new account I don't have anything from my main account wich got hacked. Please help.

:)