Someone stole my apple id??

Did you enable the two-factor authentication? I highly recommend that to avoid someone could log in using your Apple ID.

If you changed the password, they should not be able to use your info.

Please, also head to iCloud.com, log in with your Apple ID, tap "Find My iPhone" and delete all the unfamiliar devices from the list.

You can also check your device list to see if an unfamiliar device is signed into your ID.

Apple ID device list -Check to see where you‘re signed in

Change the password immediately.

If you think your Apple ID has been compromised - Apple Support

Also, set up the two-factor authentication for extra layer of security.

Two-factor authentication for Apple ID - Apple Support