Help losing weight

Ok so my husband and I are going to try to have another baby. I am obese already so when I had my first I gained about 30 lost 20 after him then gained 30 back. So I weigh about 30 pounds more than when I started last time. I am about 366 now no judging please. Ok so what I want to know is I'm going to try to cut out soda, pasta, and bread(which I dont eat much of anyways). I figure that's a start. I dont want to hit 400 if I have another kid it's already depressing how much I am now. I just want some help replacing those things with something else or what do you ladies do to help lose weight. I want to be there for my kids and not be to out of breath for things. Thanks in advance