arrrggg I'm well aware of these valleys you speak of. They seem to come incredibly quickly for me about every 3 weeks I go through an up and a down. Does this mean I am improving? Just as I am beginning to feel satisfied and that I am improving, the box is whisked away from under my feet and I'm left there hanging painfully by a thin thread which very quickly snaps along with my confidence and will to train. But I must be strong, and unlike anything else I have ever done, not give up!
The peaks are fantastic, the valleys discouraging, but you can't have a peak without a valley can you???