Made a little video for you. There are many different implementations you can use, so you don’t need to use my particular method, but it might give you an idea, how to handle this stuff :).
NOTE: The text, which is printed last is a negative value. That is, because my health value wasn’t big enough to sustain the amount of damage caused by the fall. What you do with the math is up to yourself. You can cap the “Z-value” with a “clamp (float)” value, if you want to have a limit, how much damage can be applied maximally.
Hope I could be of help.