I have very difficulty to produce breast milk. I produce only 4 oz a day. Almost give up, can anyone give me advice on how to increase quantity?

This is a "Jungle Juice" mixture that will help with producing breast milk and it will help keep you hydrated and if you don't want just plain water I do 2 litres of rooibos tea instead of plain water - I add the rescue drops to each glass I pour. They say to try and drink it within 24 hours or drink a glass with every feed you do. I have been drinking it for the last 4 weeks now and working well. Try feed baby a bit more frequently to help produce more milk and if you have breast pump it will also help stimulate more milk. I have also heard about oats helps but I don't like oats, a friend of mine eats the oats. At the moment my baby is eating less in each feed, so what I am doing is after my baby has had his feed I express so that I don't lose the milk (it drying up) and now I have plenty milk