Hello there, look like you have developed Hypothyroidism.. Hypothyroidism (underactive thyroid) is a condition in which your thyroid gland doesn't produce enough of certain important hormones. Women, especially those older than age 60, are more likely to have hypothyroidism. Hypothyroidism upsets the normal balance of chemical reactions in your body. It seldom causes symptoms in the early stages, but over time, untreated hypothyroidism can cause a number of health problems, such as obesity, joint pain, infertility and heart disease.... Standard treatment for hypothyroidism involves daily use of the synthetic thyroid hormone levothyroxine ..This oral medication restores adequate hormone levels, reversing the signs and symptoms of hypothyroidism....