My baby is five months old. I have joined my office one month back and she was taking both formula and breast milk. After I started going to the office, she gradually started to reject breast milk and fed on formula milk only. I used to express my breast milk using pump and then fed her. Since, she is not latching,my lactation has completely stopped. After expressing milk for half an hour,I get only 30 ml of milk.What should I do?