Woohoo, congrats on taking the first steps! (Again!)
Maybe setting "action goals" rather than "results goals" would be good for you. It's certainly not necessary, but rewards can be very motivating.

Maybe you can give yourself some sort of reward after a certain number of days within your ideal range of calories, or number of minutes or miles of walking.
That said, I'm a strong believer that motivation is a nice bonus, but is pretty overrated - you need to dedicate yourself to working toward a healthier you, every day, even when you don't want to. Some days you have to ignore your moods and emotions and just do what you know is right.