How the heck I got hacked?

Everyone should thoroughly check the permissions of any third-party apps, as these apps might steal your password, and then resulting in the loss of your account.

I think we’re all missing the obvious here …

OP obviously got drunk with his Russian/Chinese/North Korean spy wife, who simply used his phone while he was sleeping.

Sometimes hackers get your data by attempting phishing attacks. They trick you into sharing sensitive information such as username, passwords etc. It involves fraudulent communication that appears to come from a reputable source. To protect yourself, you should be careful about opening emails or messages from unknown senders.