Trying to lose weight, need encouragement!!

Hey ladies! I've decided to make a chance in my life, I realized I'm not taking care of myself at all. I was about 240lbs when I got pregnant last year, and did not gain any weight during the pregnancy. However, after I had him I was finally able to eat again. Unfortunately this means I started overeating and now weigh 285lbs.... I cried when I learned this... This is not only because of me eating, but also because I went from a very physical job to a job where I spend most of the day in my car, and eat mostly fast food... I really need encouragement and ideas about what I can do. I mainly eat fast food when I take my adolescent clients out during their therapy sessions. And now I am trying to only drink water as well. Any ideas?