First of all, May 1 is only 2 months away and losing 40 pounds by then is not a reasonable goal. Safe weight loss is approximately 1-2 pounds/week, therefore, a goal of 20 pounds is much more reasonable. Losing too fast is not good for your health, plus it decreases the chances of keeping the weight off. You need to develop lifestyle changes that you can stick with from now on; not just a temporary "diet".
I've never used the exercise program you mentioned, so can't say whether or not it's good. I have used Biggest Loser Yoga for Weight Loss and it does work, as do other forms of yoga, Wii Fit (if you have one), etc. Or just dancing to your favorite music.
As for food - I used to go to the supermarket on my lunch break and buy a ready made salad for less than the cost of a bag of chips, candy bar and soda, or hamburger, fries and drink. Buying ingredients and making your own salad is even less expensive. I rarely spend extra for organic.
You should center your diet around vegetables, lean protein, low/no fat dairy, good fats, whole grains. A loaf of whole grain bread costs about the same as a loaf of white bread in most stores. A box of whole grain pasta isn't much more than regular pasta. If you can't afford fresh veggies, opt for frozen over canned; you can often find frozen veggies on sale; the store I shop in, often has buy one, get one free, so I can buy extra, so I still have veggies even when they aren't on sale.
Additionally, portion size is a key, no matter what you're eating.