If the IRS hounds are at your door, download this form, IRS Form 911, fill it out and send it in. If you use it you can prevent or forestall nasty things such as seizures of your property and paycheck. The important thing is to not procrastinate but get it into the system before the really bad things start. As soon as the IRS gets this form they stop collection efforts and you get some much needed breathing room.
Of course, this won’t excuse your debt or hold them off forever. You will still need to work toward paying your debt or working out a compromise plan. Speaking to a tax professional at this point is what you need to do. While it can be costly, it cost me about $1000 when I needed to do this, it is worth it to have a real pro who knows how to deal with the IRS on your side. The stress it relieves immediately and the eventual tax savings at the end are worth it.
What if your 911 request is declined? You still have options. You can always ask for your case to be reconsidered either at the office or district level. Failing that, bankruptcy looms as the next viable option. If you reach this point, make sure you get a pro on your side though. It isn’t a do-it-yourself exercise.