I come back to a thought that makes it all stop. I desperately need to lose weight, and a lot of it. When I am doing the thought download after stepping on the scales, there are so many layers of stuff. How do I get around it?

This is the model I have got:
C: I have an autoimmune disease called Hashimoto and this effects my body in certain ways, one being it impacts my metabolism.
T: “my body has betrayed me” is the main thought. Variations are: I am never going to succeed with weight loss because of the Hashimotos, my body is working against me, I can’t trust my body, I can’t trust myself, I don’t want my body, it can never get better, I will always be fat.
A: stop before I have started, buffer with food, push it forward to tomorrow to deal with, dishonor my past and future self, write the plan again,
R: nothing changes, if anything, I get worse and it confirms my thoughts.

Since last coaching session, I am trying to get to know Hasimoto as a wise teacher of my body, a circumstance offering me to get more in tune with my body. But I still can’t shake the thought that my body should be healthy and do what it is told. That I can’t control my body, especially when it comes to losing weight. I think this might help others but not me.

How do I build that confidence and trust myself to actually do this? How do I get through black and white thinking?