PlayStation account gone?

Hi. I got a GTA unlock all from my cousin. He only knew the email and the password. That's c.a a year ago. For a year I have played on the account and all that and then. Suddenly I wanted to log in again today (no one has the data except me, my cousin deleted it) and suddenly I do not get into the account. I wrote down the password with email. What do I see? Password has been changed and the PlayStation name too. How do I get my account back? Is there any possibilities? I do not come to the Gmail account, because the password was also changed there.

Your account is now my account have changed the password Thank you, funny or kabba