Fray, losing 3lb on a *week is a phenomenal result. Seriously. If you are genuinely upset with yourself then you need to give yourself a stern talking to about what you are setting yourself as achievable targets. Some women gain 7lb or more on a star week. To post a massive loss like that and be sad about it is selling yourself short and setting yourself up to fail.
Lecture over
Congratulations! Thats a fantastic loss! (and just think how well next week will pan out after you clear the leftovers in your system out!!)