What is a word like "negate" but even worse?

I suspect this is going to be a "oh yeah, duh" moment, but I'm looking for a word that is like "negate," but worse. Here's an example sentence:

I could cram for this test all night, but the sleep deprivation I'd experience could negate the effort.

I believe this sentence means, "cramming for the test could be canceled out by the sleep deprivation." But what I really want to say is, "the negatives of sleep deprivation could be worse than the benefits of cramming.

Is there a word with the latter meaning that could be swapped out for negate in the example sentence?

EDIT: I probably wasn't clear because a lot of the answers are giving me stronger words with the same meaning of "negate." But I'm looking for a word with a different, yet related, meaning.

May be tagging it with synonyms because the confusion. But whenever I look up synonyms in a thesaurus, the list includes words with closely related meanings, too.

Negate, nullify, void, etc. can be interpreted as bringing you back to zero. I'm not looking for that, I'm looking for a word that fits the first example and means net negative.

I think outweigh conveys the right meaning here

To be more significant than; exceed in value or importance

e.g. "The benefits outweigh the risks."

The sentence in the question would be

I could cram for this test all night, but the sleep deprivation I'd experience could outweigh the effort.

A synonym that also works here is "outbalance", but that's much less commonly used.

counteract verb act against (something) in order to reduce its force or neutralize it.

void verb nullify, annul

nullify verb to make of no value or consequence

backfire verb rebound adversely on the originator; have the opposite effect to what was intended.

Obliterate

From latin, litera, it means to erase, or strike out, something. It's popular use is more on the violent side, to destroy, to demolish.

I'd use it here, it fits both popular use and historical meaning.