Time and again we see that taxpayers who run into trouble should not attempt to resolve the problem themselves. It almost always makes sense to rely on professional representation. A professional will usually reduce the tax liability by far more than their fee. But tax professionals can be expensive and not all taxpayers can afford that help.
In this case where professional help is unaffordable, a taxpayer may be able to use a Low Income Taxpayer Clinic. Many of these are affiliated with law schools. The amount in dispute must be less than $50,000 and the taxpayer’s annual income limit is approximately the same amount (varies by location and family size).
See this IRS listing for locations. https://www.irs.gov/advocate/low-income-taxpayer-clinics/low-income-taxpayer-clinic-map.