Weight loss

Would it be possible to lose 40-45 pounds by January or February? I can’t do too many exercises due to my c section right now but I’ve been drinking a gallon of water and am planning to keep drinking that everyday until I lose the weight and I’ve been eating super healthy. I’m also breastfeeding. If it’s not possible to lose it by then how long do you think it will be for me to lose the weight? I have no idea how long it takes to lose weight because I was pretty small before pregnancy but I ate so terrible while pregnant and ended up gaining 65 pounds