I Am 55 Yr Old Female With A Partial Hysterectomy

I am 55 yr old female with a partial hysterectomy (uterus and ovaries) 4/2012,. I have been gaining 5 lbs every year since and I exercise every 5 days a week and eat healthy but can't seem to loose the weight, most of which is around my middle. My Dr. has saliva tested my hormone levels for the last 2 years and I'm currently taking .5mg of Estodrol & 200mg of progesterone. Friends are telling me I must have water retention but I do not not have swelling of legs or ankles and I'm not particularly fond of salt or salty foods. Recently my dr. tested my blood for the Thyroid hormone and it is on the low end of normal so I am now taking a small amount of nature-throid as well but still no weight loss. any advice or helpful suggestions would be appreciated.