Someone added me to their family plan from CHINA, how do i remove myself and gain control of my account back?!

Ive realized today when I tried to download Microsoft word onto my iPad that my account was hacked. First it wanted me to verify my ayment info for a credit card i do not have and then it told me that an email address i dont know had control of my family plan. I tried to email that email and i got an automated message saying it wasn’t real. I then went to settings to see what family sharing was and how to disassociate myself with it and i got the above message. I do not know what to do and reading the other dicussions has proved that no one else knows what to do. Please help, I dont have access to download apps or much else for that matter because of this. I dont want to have to completely delete my Apple ID because ill potentially lose years worth of data (correct me if I’m wrong).