You'll need to check all the ingredients and check with your pade if its ok to drink the tea. Quan is also a G6PD baby and I'm not taking any nursing mother's tea/milk, just to be safe. You can try taking green papaya fish soup which some mummies swear by its effectiveness. For me, I make sure I drink lots of water and soup.
Oh, you mentioned that you are pumpling 2 hourly? How many minutes are you pumping? And do you wake up at night to pump? All these will have impact on your milk supply.