You can't access the upper level of the library from the inside. You need to enter through a window on the roof. Generally if the game is too hard it's because you don't have the right equipment for it. Going in the Volcano area without the dragon sword and the armor, you'll get pulverized in no time. There are three hints for the dragon sword: one is near the save point, the others are further down on your way to the fire temple. You need to speak to one of the monkeys to know the path to out of the labyrinth in the volcano.