The only way you've gained that much that quickly is if you're retaining fluid. Are your ankles swollen? Take it easy, do some stretches, and keep up on the nutrition until you can get back on the exercise wagon. Sometimes I have to let the body rest even when I don't want to be "down", because if I don't give the body what it needs when it needs it, I waste more time and energy on the fight than if I just woulda taken a few days off.
If I keep starting over, eventually it will stick, right?
Current weight: 140
Goal weight: 135