Hun - I tend to agree, I think you might be overdoing it and your body is letting you know about it. Breastfeeding alone is demanding on your body, plus you only gave birth a few months ago so your body is still recovering. Maybe you need to cut out or reduce what you are doing on a few sessions - Im sure you will still lose weight though it may be at a slower rate.... 1.6kg in one week is alot and you dont want to get sick from unhealthy loss hun. Hope you are feeling better soon.