How to make a lightning protection enchantment for helmets

I am trying to make an enchantment where it gets rid of lightning damage to the entity that is using the helmet. But, the procedure that I made makes it so that it has to check every single entity if it is being struck by lightning. Therefore, crashing the game/server altogether. So, I have tried making it so that it checks it on player tick, and that doesn't work and it says it doesn't compile properly. Please respond soon.