Today, 11:05 AM
I don't think you are being crazy and paranoid. Rapid weight loss can indicate health issues, and if you were borderline or underweight to begin with, it might really be a problem. On the other hand, when weight loss is desired, the loss of 5 pounds in a month is probably not "too fast."
But why blame breastfeeding? Lactation and nursing a child is a normal biological process and a normal and expected part of the reproductive system of humans. There is no reason breastfeeding would harm a mothers health, although most mothers do tend to want and need to increase calorie intake to some degree while nursing. But not some extraordinary amount, typically.
A demanding job, stress, and skipping meals, on the other hand, certainly might cause rapid weight loss even if a mother is not lactating.
and pumping "extra" in order to donate ones milk, while very laudable, is outside the 'norm' of breastfeeding, so that might be impactful as well. Producing milk does take energy- ie, calories.
If you eat lots of fruits and veges, those do not exactly pack on the calories. Maybe make sure you are also eating some healthy fats-meat, nuts, etc?