weight loss while nursing.

Ok, don't get me wrong I am not all about the weight coming off and getting " my pre baby body " back however with my first daughter I gained 60 lbs during pregnancy and lost 30 at birth then gained that 30 back by the time she was 6 months old. My Dr said it was due to nursing and that dieting could make me dry up.😲so I freak out from that thought. and now here we are 9 months pregnant with baby number 2 and only have gained maybe 20-25 lbs this pregnancy but still freaking out. I want to lose the weight I am 330lbs and I need to lose it yo be healthy does anyone have ideas that won't make me dry up?