The only way one of those firms (and only a good one and they are a fortune) can help you is if the IRS made a MISTAKE, and you don't really owe that much and you can PROVE IT.
The whole rumor that you can reduce based on ability to pay is very much different than those tax attorneys make it seem. We had a truly erroneous debt, and all the proof in the world that is was completely disproportionate to our income. We paid a huge and reputable Tax Relief Firm $11,000 over 2 years (on our credit card and went deeply into more debt) with their assurance that they could easily reduce the amount based on our income. They did NOTHING for us, because it was an accountant's doing in the first place, and we had no recourse ($s) to sue, audit, or get the accountant to amend, which was not the IRS's problem.
Also, while we had the attorneys, I still did ALL THE WORK assembling elaborate financial statements and answering every stressful notice from the IRS on tight deadlines for 2 years straight. The attorneys did nothing but fax over the occasional request for an extension-whcih I now know I could have asked for myself.
The IRS is SCARY, but not nearly as scary as those crooked law firms. Even the "legit" ones are crooked and lie about their statistcs. They RARELY get anyone a reduction, and again, only if it's the IRS's error.
We are currently in our 3rd OIC awaiting if we can settle, but we have only made progress because this time I dealt DIRECTLY with the IRS. I went and sat face to face with all or our financial info and plead the whole case to the IRS agent who had none of it on file from the 2 years with "attorneys". Don't let people scare you into getting an attorney.
You want to formally request a FACE TO FACE HEARING with an IRS rep nearest you. Contact them immediately to request that. They will not levy while you are actively dealing with them. Next, get all your finances in order for all the time that has passed since the tax years in question so you can prove you are unable to pay. Offer monthly payments while they debate it (could be around a year of monthly payments before they decide). Be prepared to pay it though. Whatever you do, don't get an attorney and don't hide. Proactively approach the IRS right away. I wish I would have had that advice when this happened to us.