First, it should be noted that based on 147 lbs and 5 ft 5 inches tall, your
weight and BMI fall within the normal category.
Per the calculator, your
ideal body weight range is 111.17 to 150.23 and current BMI was calculated at 24.46.
From the history you have provided, in my humble opinion, I believe your body may be in starvation mode. This is when your caloric intake is not sufficient to maintain your weight based on the level of energy you are expending.