it's very common dear..don't worry...it will be back to normal shape once you stop breast feeding

But my one breast is heavy

Its normal, every women will go through this while breastfeeding, Do not worry.

Feed ur baby with both breasts..

Anonymous it happens dear. It happened with so many mom's. Babies have liking towards one of the breast and drink more from that side. Another breast you feel that as big. Feed baby on both breasts alternatively. It will get better in coming months. Don't worry.