Periods and Breastfeeding

I had the pleasure of getting my period a month after birth. They are so heavy it's killing my supply and leaves my son hungry. I've drank plenty of water and it's just not working. When I'm not on my period my supply is fine so I don't need pills or tea. Do I increase my water intake even more or is it kinda hopeless? I have a stash saved up but I don't wanna dip into it unless necessary.