how to increase milk supply after mastitis

when we got home from the hospital my milk started to come in, both my breast got so engorged and was very painful; i was up until 3:30 in the morning pumping and massaging to get everything out. i’ve had mastitis twice since then and now my milk supply had a huge decrease (barely able to pump an ounce on the right side) and we need to supplement. does anyone have any advice on how to increase milk supply?! i’ve tried power pumping, lactation cookies, mothers milk tea, upspring milkflow supplement, eating oatmeal everyday and increasing my water intake but nothing seems to be working :(