trying to lose with hypothyroidism

mleeboggs

I had a baby girl almost 9 months ago and was jsut diagnosed with hypothyroidism. I have been watching what i eat and only eating 1200 calories or less a day and doing zumba 3-4 times a week for 1 hr. I have yet to lose more than 1 lbs. I will lose .5 lbs to a pound then gain it right back. I an about 40lbs over weight. Does anyone have any tips for me?