Heidrun I am so sorry to hear you are going through all this. Sounds like you felt miserable for too long. I am glad you are feeling better now
Hopefully you will be able to get everything straightened out medicine-wise to get you back on the right path and feeling better.
Do not let feeling down or illness take over your fight to eat healthy. After reading and learning about you, I would say that you are tough enough to continue on your push towards being healthy even in the worst circumstances.
Even though you may hit a weight loss plateau due to your thyroid issue, do not forget that things on the inside like your heart, blood pressure, etc. still benefit from the healthy diet. Continuing to eat healthy will benefit not just what's on the outside, but what's on the inside.
Stay strong!