How do I interrupt a shield from blocking?

Pretty much, I want to make it so that the item currently being used (specifically, a shield) gets put on cooldown and is stopped from further shielding when a certain condition is met. I figured that the Cooldown <itemstack> for <integer> ticks for <player> would do this, but it doesn't interrupt the shielding from happening. Any help would be appreciated!

(No, I'm not trying to stop the shield from being used in the first place, I'm trying to have a trigger that stops the shielding and puts it on cooldown at the same time.)