Need support

As a woman I have battled with weight loss my whole life. I lose 40 and gain 30 back. Thus time I it will be for life. I call it my lifestyle change....I think someone else already coined that phrase. But anyway I am tired of the yoyo and am ready to maintain a healthy weight for the rest of my life and I need some outside support. My goal is to run a full marathon in 5 years.