Don't fret! We all have bad weeks, and most of that weight is probably retained water from TTOTM. If you've eaten badly this last week just look at why you did so and decide how you'll prevent the same slip-up in the future. Then it's no longer a failure, it's a learning experience.
You can do it! Remember it's the long term perseverance that counts! Little fumbles along the way are to be expected. As long as you get back into it then it can only make you stronger in the long run!