My initial thought is that you are trying to drop too much weight too fast. The principle of weight loss is the same no matter how you approach it. Burn more calories than you take in. You can loose weight without exercise. Smaller portions at meals. Dried fruit for snacks.

My own weight loss was 35 lbs over 8 months. Thus far I have kept the weight off for 5 years. The cycling helped but I would still be overweight had I kept eating and drinking as in the past.

One thing that helped me was to weigh myself multiple times a day. Not to see how much I had lost or gained but as a reminder about eating right. Even if racing is on your list of goals, if you drop the weight too fast you will be inclined to put it back on.