Breastfeeding Hormones????

Hello ladies I was exclusively breastfeeding my baby since she was born. She is now 15 m old and has decided to stop. She has been doing great with a bottle and regular milk. But I am definitely not ok!!! I gained about 8lbs in less then a week. Which I’m so confused because I try to eat healthy and work out 6 times a week. My body feels somewhat swollen or puffy. My Face is covered in pimples and to make things worse, I feel very sad, overwhelmed and irritated. Anyone else felt like this after they completely stopped nursing?! If so, how soon did you feel normal again? How soon did you start to loose weight? Please help me out.