*** See your doctor! *** hypothyroidism slows down your metabolism and as a result the other systems in your body scramble to try to compensate the best they can. Sometimes your body will go into "starvation mode" and pack on fat as protection when your metabolism gets too slow. The rest of your hormonal system gets confused too, your estrogen production has probably decreased badly and that's why you're getting symptoms like menopause..
I don't think that you are suffering from hypothyroidism because your symptoms do not match those of hypothyroidism. You would be gaining weight instead of losing weight. You need to see a doctor as soon as possible for diagnosis and treatment.