what convinced you it wasn't the truth and that leaving wasn't a horrible decision that everyone in the truth makes it out to be?
First off, take this sentence and ask if it is really true, the second part.
"Everyone in the truth" says it is horrible, why?
Could be a number of reasons. They fear death. They fear missing out on everlasting life. They fear that they will screw up their life outside of the cult. And finally they fear shunning.
Only one of the four is actually true, the shunning. If you mentally free yourself, and prepare to live a full life outside of the KH walls, the only real obstacle is the shunning.
Almost everything in JW world relies on "thought stopping" techniques, so any claim made is not fully examined as to whether it is true or not.
As to your original question, my investigation of past WT writings revealed that they had never once, EVEN ONCE predicted or prophesied anything at all that would show they were backed by a supernatural entity. Once I realized they had a 100% failure rate when it came to predicting the future, I felt no need to listen to another single thing they uttered.