When I first started to lose weight and hadn't met with my nutritionist yet, I started by eliminating soda and obviously unhealthy snacks (chips, cake, etc.) and adding in more chicken and vegetables. I also started out with small bouts of physical activity to increase my endurance.
These small changes got the ball rolling and I got addicted to my healthy eating and getting my exercise in. I couldn't believe when I lost my first 10lbs, it was a miracle. It turned into losing 150lbs in 10 months and now I'm more or less maintaining as I haven't dedicated myself to losing more. The important thing is that I know what and how to eat now and will never ever gain this weight back.
I wish you the best of luck. My experience is nothing short of a miracle and if I can do it, anyone can.