Someone has gain access to my iCloud and all my device data

See this:

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

If your Apple ID account has been compromised, you will need to gain back control of your Apple ID. Change your Apple ID password, if it has been changed by someone else, reset it. Head over to appleid.apple.com to make any changes to your personal or security info that’s not quite right or that you don’t recognize.

If you are unable to reset your Apple ID password or access your Apple ID, proceed to iforgot.apple.com to initiate the account recovery process and regain access after a designated account recovery waiting period.

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