Actually my iPhones privacy/security has been compromised and I am not here to convince you. I’ve went into Lockdown mode as well. I’m here for solutions.
The solution is to stop listening only to yourself. Otherwise, why would you even bother to post here?
Your phone has not been hacked. It cannot be done remotely - at all. Period.
What does get hacked is a user's account. And that can only be done if someone else guesses, or knows both your Apple ID and password. With that information, they can login to your account as you from any other device and see everything you do. Emails, messages, contacts, etc.
Go to https://appleid.apple.com/
Sign in with your ID and password. Once in, click on the Devices link in the left column. Any device listed you don't recognize is that someone who shouldn't be there.