That does not sound normal, that shouldn't be this way. 🤔 Can you check your "World Settings" (press ESC)? There is one setting for "Player Damage" - the damage you make to enemies, trees, limestone, rock, ... This can be set to a negative number, so that you make less damage to things.
Can you change this and maybe just try different settings? Does it make a difference, when you change this setting?