Maybe you're not using ICM correctly. In terms of fixing that I would recommend two things. One, take ICM quizzes. They help give you a feel for what the right answer is. And two, review your pushes (or decision not to push) after the game. Put them in an ICM calculator if not too inconvenient. Maybe at least pick your one or two most questionable moves.
Another possibility, however, could just be variance. You listed 4 outcomes. That's not a large enough sample size.
As for playing like a nit, as others suggested, I generally agree. It's the easiest way to play. But don't get carried away and get anted / blinded out. Also, look an see if the player (or two) on your left are also nits, and if so, be sure to try an occasional blind steal.