Hi Laura,
What's done is done. Sometimes you need something like this to make you realise just what you have to do. At the moment you feel awful - you won't want to feel this way again and that is what will help you to stick to LT in future.
We all have times when we feel tempted - I know I have - but I've read so many posts from people that said how bad they felt having done it that I was determined not to.
Consider it lesson learned and you are a better person for it!
Good luck for the coming week.
x