I've tried completing this dungeon about 7 times already but I also ended losing to Phytops because I can't get out of the way of its vines.  Other than that, the dungeon can be quite easy when you know what you use(Cough use the whip for 80% of it).  Can you use potions in the mini-game dungeon?  I think I'm going out of my mind.

Minigame dungeon? Que?

The dungeon with a series of rooms with monsters to defeat.  It's in Castle Town.

Oh, that one. Are you in Level 2 or Level 3?

I'm currently at Level 2.

Right at the end, then. Level 3 is gonna hurt ya, but it's a lot more fun.

Listen, I forget exactly what's in level 2, but Phytops remains the hardest fight in the game for me. When he gets to whipping his tentacles, you need to be at the very edge of the platform, running from side to side - preferably toward the side of whatever tentacle he struck with last. If he starts turning and you need to hit him with a thorn from one of his tentacles, run toward the tentacle moving away from you so it doesn't hit you and cause you to lose the thorn as soon as you grab it. If he DOES hit you, grab another thorn and throw it at his eye while you have the invincibility frames after being damaged.

Also, don't use the whip unless you need to remove shields. Arrows, bombs, and the boomerang are all better for dealing damage. Bombs in particular will kill any Stalfos (including Captains) in one shot and the Stalfos will not dodge them.

I only have the whirlwind, bombs, boomerang and whip so far.  Also I see what you're saying about Phytops.  I'll try it in a few.

By the time you get to level 3.... you'll see what I mean. There'll be a particular room with three enemies, and do NOT use your items on them. They take an absurd amount of damage to kill and are slow enough that you can safely beat them to death with your sword.

Yes, you can use potions in this place. Bring at least a blue one for the fight with Phytops. A red one wouldn't hurt either.

Did you manage to finish?