Yes his wickedness was his undoing, I just wanted to point out that his fears were justifiable. There were a number of beings out there capable of using the ring against him. And considering he was right to believe noone would actually intentionally destroy the ring, that not even entering his head was at least somewhat forgivable. It was pure luck the ring was destroyed instead of claimed by frodo or gollum (or even sam if it came down to it) and then swiftly returned to its true master because none of them have the power to resist its corruption or use it properly.