I Took Lithium For A Year And Then Stopped But

I took Lithium for a year and then stopped but my weight keeps going up. I've gained almost 50 lbs in one year. i cant fall asleep unless I take sleeping pills , my hair is braking off, my doctor says I need to exercise even thought she knows I've been a runner my whole life. I'm not lazy and liquid diets don't work.HELP!