Sounds like you were a victim of a phishing attempt where you inadvertently gave away your password. None of what you described is possible without the other party having your Password and if you have Two Factor Authentication, the verification code sent to your device would also have to be entered if access was attempted on a device that had not previously signed into your account.
Recognize and avoid social engineering schemes including phishing messages, phony support calls, and other scams - Apple Support
While you mention the account being hacked, it really is nothing more than a scam. Not much different than sending someone a Gift Card with one of the many Gift Card scams. I assume you used Account Recovery, which does not require access to the Trusted Number, but one of the possibilities is that you will no longer have access to your account. In fact, this person now has the ability to completely delete your account. When using Account Recovery, there are conditions that will cancel the recovery request, so make sure you read that information carefully.
How to use account recovery when you can’t reset your Apple Account password - Apple Support