I want to add a script to the player that does something every time the player is physically hit. This is easy by simply putting the code inside the OnHit event, and testing if the source of damage is a Weapon. But my issue is that I need to know how much damage was taken on that hit.

So, is there a way to identify the amount of damage taken from inside the OnHit event? Any other way?

couldnt you do a get actor value on health before and after the on hit event, then calculate the difference?

The idea is good at first, but how can I keep control of the correct actor health?
I could save the actor health after each hit and compare that value to the current health on the next hit. But after a hit, the actor can be healed or lose health through other means that don't trigger the OnHit event, so I don't think I can have control of that health.