Breastfeeding and losing weight

I need some help and or tips on how to safely lose weight without losing my supply. I tried to diet a week ago and ended up severely hurting my supply! Im one of the unlucky ones who gained weight breastfeeding. I was soo incredibly hungry when I first started to breastfeed. lol It was kind of strange because all throughout my pregnancy I really didn't have an appetite. Then all of a sudden it's back full force with vengeance lol. Any help would greatly be appreciated!