amen to the above comment....i lost 40lbs (well, 56lb) a couple of years back and found running/jogging a really good thing. obviously changing diet as well.
there is no getting around it - diet and exercise is the only way.
even if you can only make it a few steps and then walk a bit. you will be suprised how quickly you will see results. i went out for roughly 20 minutes covering only a quarter of a mile to begin with. when i got back i did some stomach crunches, beginning with 3 sets of ten up to the middle (hope you understand this!) and 3 sets of ten each side (eg. left elbow to right knee). and don't rush - take as much time as you need - used to take me roughly 10-15 minutes.
i began to see results in two weeks, i swear to you!