I will advise you to stop worrying and take more than 3.5 water everyday the more water you take the more breast milk you will get do not worry but still if you are very much into trouble then I will advise you to start formula for your baby but nothing is best than a mother's milk so if you are milk is coming I will advise you to set a schedule for your baby to drink and after every 2 hours you make your baby drink the breast milk or if baby is not taking you try to express it out with help of a breast pump or manually with your hands but make a schedule this will help 2 signal your body timely also you can take lactare capsules to increase breast milk