I hate the gym so I work out at home. Try some workout tapes like the Firm workout series, it shows how to use weights and shows modified moves for beginners. I even have some of Susan Powter's old workout tapes (remember her, "Stop the insanity").
Yes, fast food is a no-no. Can u switch to diet coke? I hated it and eventually switched over and now I love it!
Obesity has all kinds of medical problems, heart disease, diabetes, higher chance of stroke, etc. Not to mention no energy, feeling like u cant do what you once could, feeling older than u are...u are so young, you can definately take control of this.
But look on the bright side, you got a man who loves you. Thats not easy to find!

Take care!