If you have tpo antibodies with 11.85 tag with clinical signs and symptoms, you are hypothyroid. In such a case thyronorm should not be stopped. Dexamethasone suppresses tsh mildly and the drop is probably due to thyronorm. Dexamethasone suppression was a test for cortisol excess which is a different disease. The tsh reading after 10 days is also of no value. A proper diagnostic approach will lead to effective therapy.