You are doing the right thing by increasing your fluid intake. So continue drinking at least 8 glasses (8 oz) of water/liquids. Avoid caffeinated products. Protein rich foods are all daals, eggs, meats, and nuts. Milk also has protein. I do not know if you are a vegetarian, but either way you can increase your protein intake my increasing the foods from the protein rich group. Please continue to see your doctor to keep up with the amniotic fluid status.