I owe 18k to the IRS

Because I'm an idiot and have been doing my taxes wrong for 5 years. To be clear I'm not trying to get out of this. I realize I made a mistake and it's my responsibility to fix it, I just want to do that in the smartest way possible. Also, I wasn't partying with this money, I was paying on my student loans.

I don't think I can qualify for an offer in compromise, because I'm employed, will make over 100k this year, own a home and have money in retirement.

It looks like the interest rates that I would pay both for state and federal are 8%. I just had a house related emergency that dipped into my emergency fund by a couple thousand, so now I have $18,000 in my emergency fund, $4,000 in a new car fund and $1,500 that I was going to use to start my 2025 IRA. All those are in a HYSA earning 5%.

Here is my plan, please give me some thoughts on adjusting.

Step 1. Eat a frozen pizza and feel sorry for my self for a maximum of one night (already started)

Step 2. Pay what I owe to the state ($5,000) with what would have been the new car fund and IRA money

Step 3. Wait until the last year of amended returns is accepted by the IRS and make a payment plan with them. The year that hasn't been accepted is only a partial year and so the amount I owe will be small. Without that year accepted I can't get a final number but it looks like my payments would be about $350 a month for 3 years.

Step 4. Pay that down as aggressively as I can, since I do think the interest will be about 8%.

What I actually want to do is pay off the whole lump sum of both in one go and then pick up overtime and cut back on retirement until my emergency fund is replaced. In 2024 I maxed an IRA and a 457 by November. If I paid them off all in one go I would still have 34,000 between what is left in my HYSA and my checking.