5" 9 240 pounds wants to lose 50

I have been such a pessimist in my life, and now at 25 i regret all the lost time, i want to get myself on track, i have the insanity workout DVD's and sumba, but i have had such a hard time getting myself to do them on a constant basis. I live in a third world country with a very limited income and i find it very difficult to get into a diet plan that is within my price group. I also support my mother and younger sister.

Im lost at the moment does anyone have any tips for me to follow?

oh yeah i also smoke a pack of cigarettes per day and i hope that getting into a routine will help me stop that horrid habit.