NEED HELP!!! I have a question about weight loss!!!?

Well I'm 5'4 and 203, gained weight primarily from birth control 4 years ago, gained seventy five lbs in 3 months from the bc, had one child before taking it and maintained a normal weight of 145 for myself until i went on this med after, had another baby after it and now can lose weight at all. i walk/ jog 2.5 miles a day and eat one meal at dinner, drink nothing but water and eat minimal carbs no weight is coming offf....... my walking route is half up a steep uphill and don't understand whyican drop lbs???? please someone help me...