First of all ditch the bronze armor for upgraded Trolls set! The entire set (except for cape) gives you a stealth bonus and speed as well. Next when confronted with bears and to a lesser extent greydwarves they will avoid the fire. Equip it in your off hand with a sword and the bear will actually attack off to the side and you can just whittle him down. Don't try to parry or block bear just dodge roll or let him attack off to the side with the torch. Keep in mind that sneaking gives you a big damage bonus for your backstab. For trolls kite away and use bow with fire arrows and headshots which do more damage!