Have lost all access to my yahoo email account since I had to change my password after a scam attempt four days ago

Cannot log in to my yahoo email account or receive messages for four days now. Inputting new password just creates a doom loop whereby a six digit code is sent to my iPhone, I input it, it is not accepted, I am told to call a Sky helpline (my email has a Sky.com address)-they say they have never met this problem and cannot help. I am housebound and live on my email and am getting quite desperate PLEASE can someone help?