i cant link any platform

latestly i bought ea fc 25 from my steam account and i tried to link ea with steam but whenever i try to link it, it says that another e-mail has already linked and tries to send the code to the old account's gmail,but here it gets confusing,the old account was linked with another gmail which i cant detect or get into i tried many different ways like changing the email of this account or the password but it doesn't work,does this have a solution?