Does draining your 401k ruin your credit?
Not directly.
But the taxes can.
Withdraw funds, and the IRS issues a 1099-R.
Ignore it, and you're on the hook for income tax plus penalties.

Skip the form?
You can still pull IRS transcripts online
and clean it up with tax software.

Moral of the story:
Don't panic.
Don't guess.
Check your documents.
File them properly.

Because with retirement accounts,
mistakes compound faster than gains.