I think it's good ol' classical conditioning. It's the same thing that happens when you get drunk on (pick your fave drink) and then cannot drink it any more because you think it makes you sick. No, too much of it made you sick, but I can understand why it's not on your fave list any more. You have made the association with that drink and feeling horrible next morning...or all night long AND morning.

In this case, you have had several unexpected shocks, which by themselves are distinctly unpleasant. However, they signify a change in your heart's condition, possibly a deterioration that has begun to assert itself, and that is worrying. Who wouldn't feel that way with an ICD doing what it is meant to do?

You will feel somewhat better once you and your cardiologist knows what has changed, and if it can be managed. If it's the ICD, that can be fixed. If it's you, you might be able to be fixed. And then you can forget about any more shocks. But I would hope, and try, to convince you that the ICD is probably doing what it was engineered to do....................FOR you. Yeah, it's a sudden and swift kick in the pants, but...you need it....maybe?