Weariness in it’s current implimentation is way to penalizing in a fight. The increase for the time it takes to do something is fine for normal tasks like crafting, manual labour or sorting things out. But it doesn’t make sense that someone would slow down so much that a slow attacker like a zombie would be able to get in 5 punches, scratches and bites before you muster up the energy to stab him with a steak knife once. The urgency of such a situation would mean you wouldn’t just take it slower becease you are weary.
It would make more sense to have attacks and movement not be affected by weariness the same way normal activities are. But instead have them be indirectly effected by direct and visable penalties to speed, strength, dexterity as well as reduced max stamina and stamina regen.
Just some numbers I thought up (might not be ballenced or realistic):
Lightly weary: -5% max stamina and stamina regen. Nothing to major and not really noticable.
Moderately weary: -2% speed and a -15% max stamina and stamina regen. The reduction to speed should give a visable hint to the player to see that it is having a impact on their abilities.
Weary: -5% speed, -1 strength and -25% max stamina and stamina regen. You can still fight if you need to but will do so at a real disadventage.
Very weary: -10% speed, -2 strength, -1 dex, -30% max stamina and -40% stamina regen. This is the point where you really should be avoiding fighting or danger of any kind
Extremly weary: -20% speed, -3 strength, -3 dex, -40% max stamina and -60% stamina regen. This is the point where fighting is only a absolute last resort as these penalties combined with pain will quickly cripple you.