I realized I was no longer a JW in my mind when the guilt was gone.
I was trying to make a decision one day and I remember thinking that I wanted to make the right decision so I wouldn't be living with guilt. Then it hit me - the guilt from being a JW was gone. At some point it had completely dissipated and I didn't even realize it until that moment.
When I no longer lived with that guilt is when I knew I was truly free.