Yeah, read Mighty's thread for an example where all was not as it seemed for her ex living with the OW.
And I second the bucket list. Set some fun exciting challenges for yourself. Just imagine: if you knew you were going to get hit by a truck in a year, would you be wasting your time and energy on what he's doing, or would you get out there and LIVE?
How about making a list here of ten fabulous things you would like to do or learn this year?