I think I had a couple of bad colds that really decreased my supply. I just tried to nurse more often (well, DD was asking for more!) and my supply returned on its own, before I felt totally better from the cold. I was like, hmm, milk is back, so I am probaly getting better as well! Also your milk will protect your baby from getting your cold, so keep nursing! (A friend thought she had to not breastfeed during her bad cold and ended up having to exclusively pump after, which was really hard for her). Good luck & hope you feel better soon!