Julia M - I'm so sorry about your disappointment. Losing weight is such an emotional thing, and I hate reading the sadness in your post. Are you near goal? Maybe the number you've picked is too low for your body? I know I'm 5'10, and WW says I can weigh between 142-174. Anything below 160 would be far too thin for my body type, so maybe that's it?
I second what Robinb posted - eat ALL your points. ALL of them. Just for this week, try to lay off the franken-food, eat the real stuff. Full fat, not fat free. You'll use less for the flavor, but be more satisfied. Are you good at tracking? Look back on your weeks that had good loses, and see what worked for you then.
Are you exercising a bit every day? A bit is about an hour - not hours on end. Are you getting your heart rate up every day, for 30 minutes or so? If you've always done the same exercise, maybe switch it up? For example, if you always walk/run 3 miles, maybe take an exercise class or swim laps?
The only other thing I want to (gently) ask, is, what are your personal goals to weighing less and getting healthier? It's so hard to type this out on a message board, and have it come through the way I intend, but your post talks about being "good" and how hard it is on you to have weekly disappointments. No food is "good" or "bad", at least not on the WW program. If you want to eat a whole cake, okay, not the best food choice, but just make it work into your points, and don't do it every day. Are you really going to live the rest of your life having a lettuce burger and cream of wheat every day? You could, but I don't think you'd enjoy it. WW is a lifestyle plan, not a diet plan. I think, from the way your post reads, that you are being very, very harsh on yourself. Losing weight, getting healthier, is a journey. You learn what works for you and what doesn't, what you're willing to do to be the best you you can be.
Taking care of you is ALWAYS WORTH IT. ALWAYS. You say you don't know if it's worth having the weekly disappointment at the scale - so go to your meetings, and when they weigh you in, to not write it in your book. You are not defined by a number on a scale. None of us walks around with our scale number on our back.
I hope today is a better day for you. Big hugs for you - getting healthier is such a struggle, but it's so, so, worth it - because you are worth it.