Undertale: I used all my good heals fighting Undyne. Am I gonna have a Bad Time?

[Razade]

Well, I know I'm about to. I've been asking for a bad time since the beginning. I just defeated Mettaton, dealt the poor guy nearly 1,000,000 damage, and went to stock up on the best heals I could afford at the MTT Resort.

But I'm worried they won't be able to heal me enough. Now, I expect to die a lot, I've heard this fight is even harder than Undyne. But any advice?

Stop now. Delete your save. Go play a better game. I suggest Ori and the Blind Forest or Enter the Gungeon.