Small spoiler below

I just recently rediscovered Zelda Classic, and decided to dust off a map I remembered loving but never finished: ALTADD. And I kinda broke it. After I got my White sword and went back to LW3 I went over a few rooms and decided to see if i could use the bomb trick to jump over the hole. Turns out I could. Then using the boomerang and the red candle I managed to kill the Lynels in all the rooms until I stumbled upon a golden sword. I was hoping for a cool item but I didn't expect a sword. And either way I can't pick it up with six hearts right? NOPE I was able to take it.

ANYWAY, My question is, what sword did I pick up? Is there more than three swords in this game? And can I pick up a weaker one thus forever losing my stronger one?