Player damage resistance

So I just got a server so me and my friends could play together, but for some reason we all take increased damage from all sources? Every setting is default except xp, taming, and harvesting. We all get knocked out from one punch from any one of us (with 0 melee investment), we all die instantly from a 10 feet drop, and punching wood kills us faster then we can collect a reasonable amount. How can I fix this? Also some other funny details are that we seem to get a LOT of stats by leveling up (100 weight per level), and even though I put a server password on it never asks us when we join. Again the only settings I changed was xp, harvesting, and taming, which are working as intended. Any help is appreciated.

No I didn't change it, it is at 1.0. I even tried lowering it to 0.5 but the only thing that changed was me and my tribe mates couldn't damage each other at all anymore, which was weird (we were still taking the same amount of damage from other sources as before, like punch damage recoil and fall damage). I have since then changed it back and I'm still having the same problem.