I think this is common problem, for most of us...I'm trying to figure out that for myself also, and currently I came to this 2 questions:
1.) What would I be happy do to every day of my life, from now until I drop dead? :D
For example, maybe you would enjoy dancing all your life and drinking smoothies for breakfast, or maybe doing yoga, or hiking, running,or walking (maybe while shoping :) ) etc.
Second question is additional if you are not able to do that "your dream thing" right now, maybe because your body is not ready:
2.) What should I do short term to make me able to do and enjoy the 1st?
And ofcours..take it easy, go step by step, you have whole life to be that fit and healty person :) start small, but do it every day...don't focus on loosing weight, but on becoming that person that takes care about her body :)