Rant: post partum weight loss, I don't get it!!!

So with all my pregnancy's I've dropped the weight pretty quick. Well I just had my baby on Dec.28. During my pregnancy I went from 135 to 178. I was extremely swollen after I had him, more swollen then I've ever been! Anyways I went to the Dr today and I weigh 168. its been 3 weeks and I've only lost 10 lbs. I've barely had an appetite and I'm breastfeeding. ugghhh I don't get it. I thought I'd for sure lost atleast 20 lb. Any tips? I had my 5th csection so I can't do exercises yet.