Breastfeeding mom needs to lose 75 lbs

When I got pregnant I was 190. Fortunately, I only gained 23 lbs. The weight flew off after my son was born. I lost the 23 lbs plus an additional 7 by 3 weeks postpartum without even trying to diet or exercise (which was pretty much impossible after what I went through with the labor and delivery). But slowly the pounds started to pile back on. Now I'm 3 months postpartum and weight is hovering around 198-199. I've always struggled with my weight but this is the biggest I've ever been! It's time to change!!! Anyone have any experience losing weight while breastfeeding?