Insomnia

For insomniacs: what do you do late at night when you can't sleep? 
Tonight I cleaned for 3 hours hoping it would help.
Any suggestions on how to get to sleep? It's 2:30AM my time.
I usually can sleep but tonight I can't.
My career has me overly stressed lately, I think that's been playing a role. This new insomnia popped up about a month ago.