Need to build supply badly

Ugh. I Am Really Going Through. I have a 7 week old beautiful baby boy. My 2nd day I brought him home I were producing around 5-6oz every pump session. Around every 3 hours. I had a great supply. I started lacking on pumping. . . . Horrible mistake. I suppose I got big headed when I start stacking away in the freezer. Now today I am pumping 1.5-2oz every 3 hours. I am drinking lots of water. And also drinking mother milk tea constantly, took my baby too the doctors today and he only gained 1oz since last week appt. I'm trying to find natural ways to build my supply. I really don't want to supplement, due to I already tried twice. . He throws the milk but for about 5 hours straight. And I just can't bear doing it again. He does have alot of pee diapers so I know he isn't getting dehydrated. Any tips mommies . Please anything will help.