The most important thing is to either come up with a plan or buy a workout plan that you will follow for 4 weeks. This will keep you focused on daily tasks (workouts, eating habits, stress reduction strategies) you need to perform to reach your weightloss goal.
It will also give you something to work on which can be a good thing when you're going through a break up. I doubt you gained 7 pounds over the weekend. If you did binge then it's probably water weight but it's best to have a plan of action that will help you be healthy and feel good about yourself instead of leaving it to chance.
Here's a great step by step plan to get started. It's free.http://www.freeworkoutsguide.com/weightlossdetox.html