Get a new target!
Anything, really, but set your mind on achieving something small, and relatively quickly. Say, for example, losing 3lbs in two weeks, or getting under a stone barrier.
It could also be an exercise goal.
Start work on the Couch to 5k running plan perhaps?
The advantage here is that you'll feel like eating healthily when you up your exercise.
Why not try a water challenge?
Try to drink 3-4 litres of water every day, and see what difference you make.
Another idea is to watch some TV.
Seriously, there are loads of programmes on just now about eating disorders and losing weight, and I watch a lot of them and they help keep my mind focused on what I want to do, and stop me thinking about eating crap.
Most importantly, go to your meeting/weigh-in tonight, and try to take part in the class - the feeling of involvement might fire up a mutual goal with others, garner ideas, or even create competitiveness with other class members.