Note: be sure you file your taxes. You legally have to file, whether you can pay or not.
Once you file, after two years the debt can be part of a bankruptcy, but you have to keep filing.
As you know, this is a really sucky spot to be in. I believe the IRS has a program for people who have no chance of repaying -- not sure what the title is. It's worth looking into.
You did a brave thing coming online with this. I imagine a lot of folks would just call you names and be done with it. Speaking for other guys in the same situation, thank you.
Good luck!