You don't need your shaker to make shakes. I've never used them! Mix it with just a LITTLE bit of water into a thick paste and dilute slowly. Works very well.
DON'T fall into the guilt cycle, you are worth so much more than this. You HAVE learned a lot, you are recognising the fact that you have done too much at the same time. Would you have known it previously?
Giving up smoking in a long process - do you think I gave up by going cold turkey? No. I still had one on occasion, just further and further apart, until it was just 1 per month, then 1 per 3 months ... now it's none. It's a long process of 'healing' and learning from blips and mistakes.
We're not perfect. I'm not perfect and neither are you.
Write down all the reasons why you went on this diet in the first place. Then write down the reasons why you should keep eating and sabotaging yourself. I bet they will seem a little silly.
I KNOW you can do this. We all stumble on the road to success. We just have to keep trying to get there. Imagine if all those who believed in something crazy gave into doubt and shame over what they were doing... we'd still be living in caves gathered around a fire!
Pick yourself up. Now. Do it. What's stopping you?