Please understand that thyroid , blood pressure and diabetes are chronic disorders and will require lifelong treatment. It is better to stick with some doctor who can take care of your health in the long run. Reach out to him and don't take suggestions from anyone who has no idea about your condition/ disorders/clinical history , you will be surprised by the variety of responses which will confuse you and lead you nowhere.

The dose of the thyroxine depends on the body weight . In subclinical hypothyroidism dose of 1 mcg is given per kg body weight (eg in a 50 kg person dose of thyroxine 50 mcg will be given )and in overt hypothyroidism dose of 1.6 to 1.8 is given per Kg body weight . The target TSH after starting the treatment should be mid normal of the reference range . So you would actually need to increase the dose rather than decreasing it .