icloud help, my account was hacked
i have received an email from Apple that someone signed in on MacBook pro by my old iCloud account. If he could read my old messages when i had turned off iMessage on iCloud? I don’t know how long he was using my iCloud because I have always checked my devices and never noticed smth like that could you help me? I have deleted my old account and wont to make sure that my old messages and photos are safe and deleted, and he could never seen them.
whan i have turned off my iMessage from i cloud, could someone else can see my messages on other devices which is using my iCloud? Please help me it’s very important