Postpartum Weight Gain

As a bigger person, I was very cautious about gaining weight during my pregnancy and was successful (I gained about 25 pounds). But 6 weeks PP I find myself HEAVIER than the day I delivered. I'm exclusively breastfeeding and I'm hungry all the time. I feel disgusting...my sweat pants barely even fit! I started weight watchers today which will hopefully help me drop some weight before I go back to work in two weeks. But has anyone else ever been having this issue too?!