dude here's the biggest tip I can give you for Zelda 2:
scattered across the overworld are lots of little sacks of XP and one-ups and stuff.
both of those are permanently lost if you die, yet don't respawn.
so only get the XP sacks when you KNOW you're going to level and not lose all your lives and have to continue.
i would not get ANY of the overworld one-ups on the second continent. then, once you're ready to take the Great Palace, every time you journey there, grab 1-2 one-ups (and, obviously, don't save or continue if you do perish, just reset) and I guarantee you'll have a much easier time with the game.