Why can’t I lose weight?

So ever since I had my second baby in summer 2020 I have been carrying around about 30 extra pounds. I have been exercising 5x a week, doing strength training as well as walking about 2 miles a day pushing around a double stroller in my neighborhood, even up and down hills. I honestly don’t eat that much, and I eat quite healthy and clean. I don’t eat junk food at all, I don’t drink soda or sugary coffee, I am even still breastfeeding which is said to burn like 400 calories a day. So why can I not drop a single pound?! No matter what I do or how little calories I consume, my weight is staying exactly the same. I’m so frustrated and feel so bad about myself and I’m scared I’m going to give myself an eating disorder.