iCloud account recovery after trusted number change and Gmail hack

My gamil can be hacked by someone and change my icloud account trusted number I can logout my ID and 3 to 4 days my ID can remain logout and when I want to login my account I can't login my account I try to reset my password and put my Gmail but I see that trusted number can be changed and I don't have access to that number There are no other way to reset my password I have all the information about my account I have a lot of data in my account that was important for me

I want my icloud account recovered

Kindly help me in this procedure

Thanks!

[Re-Titled by Moderator]

Original Title: iCloud account recover