I Owe the IRS but Can't Afford to Pay
The IRS has options for people who genuinely can't pay. They deal with this every day.
If you genuinely cannot pay, the IRS has a formal status for that: Currently Not Collectible. When you qualify, the IRS stops all collection activity. No levies, no garnishments, no phone calls. And the 10-year collection clock keeps running.
If you can pay something but not the full amount, you may qualify for an Offer in Compromise (settling for less) or a partial-pay installment agreement (monthly payments that don't cover the full balance before the statute expires).
The worst thing to do is nothing. Penalties add 25% or more to your balance. Interest compounds. A $20,000 problem becomes a $50,000 problem if you wait long enough.