I've owed the IRS, or at least they said I did, long story, ex didn't pay his so they got it from me several years after the divorce. . .
I know they, the IRS, can help you and you can fight it, you can have hearings on it and all that. You can show them that you dispute it and give them the proof. You can make payment arrangements or you can try an offer in compromise deal too.
If you are in recovery. . .then you are just dealing with more wreckage of your past??? Just be willing and see what happens. That's what my sponsor told me.
For what it's worth. . .The IRS was on my resentment list in a couple of my 4th steps!