need help unlinking hackers email from steam link

a while ago my steam account got hacked and one of the things the hacker either did or set up a program to do was create an ea account and link it to steam, why? i have no clue but essentially what that means is because im trying to play skate off of steam i cant sign in on any other email other than the one the hacker set up, it just comes up with the window i put below when i try. to be clear i am very sure that isnt any email name that i know of at all. would appreciate some help by unlinking the email or something, thanks.