We've all been there. Its always "well I was hoping I would've done this by this certain date/time." Here are a few things I remind myself....
1) The great part about waking up in the morning is that today is a new day. Whatever happened yesterday is in the past and cannot be changed. Whatever is going to happen tomorrow is tomorrow. I am in the now and I have to take it in.
2) You are NOT going to lose 50 lbs in a day. As much as we would all like to wake up and magically be at our goal weight in the morning... its just not going to happen.
3) We all get motived and like to think "oh man I'm going to start a completely different life style, everything is going to change tomorrow." That's not REALITY. It doesn't work like that (for most people). Some smokers stop cold turkey, some have to gradually quit, but at the end of the day, they all reached their goal, one way or another.
Its not always about becoming a gym rat/health nut like Caroline said. Sometimes its just a matter of making SMALL changes that always add up eventually. Take the stairs instead of the escalator, park in the back of the parking lot instead of right at the door, drink 2 glasses of water instead of the ONE you usually drink. Only eat a SMALL fry instead of a large, or drink a diet coke instead of a regular coke.
They don't seem like much but they are MUCH easier to maintain. I find that when I tell myself "NO YOU CAN'T HAVE THIS" it makes me want it THAT much more. [I'm the stubborn, hard headed 'you can't tell me what I can or CAN'T do' type]Then I obsess over it and eventually, I'm going to cave in.
So dust yourself off, pick yourself back up, and just look at the schedule for when the next wagon is going to be coming through. That way you're at least on the road to getting back on it.