Wow! What a fabulous start to a new you. I have a couple of ideas that may give support. Depok Chopra has a couple of books on health that are great. He will give you ideas on how to vary the diet to keep from getting bored and falling off the wagon entirely. I love his description of the healing power of the body.
Check out qigong (chi gong) as a form of easy soft exercise to help get fluids moving and energy flowing in your body. Chi gong connects the mind with the body through breathing and moving. Yoga has some breathing techniques that will support you during these major changes you are seeking. I prefer Yoga International, a magazine that leans more toward the meditative side of yoga.
I'm finding the more chemicals and additives that I eliminate from my body the more weight I am able to lose. It's hard for me to be 100% but every bit helps.
Just having such concrete goals is a giant leap forward. Keep a copy of them handy where you can see it often. Try "feeling" as if you are already 50 pounds lighter. Imagine the increased spring in your step. Visualize what your body looks like and how it feels. Really get into this visualization and feel it. One of the sources for this is Chopra's book, Grow Younger, Live Longer: 10 Steps to Reverse Aging. I admire your determination. It will certainly improve your health and quality of life.