I get these from time to time if its the same thing, it's called pilonidal cyst but really is an abscess. Soak in a tub, as hot water as you can bear. If that doesn't help you'll probably need to go to the doctor sooner rather than later before the infection spreads into the bloodstream.
Bleh. On top of it all, my GI tract is saying NO to the corn pops I ate this morning, and I'm crampy. I'm just full of loveliness today.