Wanna try it the Right way.

Today is my first day on Myfitnesspal. I can't really say that I've struggled with my weight most of my life because I have pretty much always been about 20-40 lbs overweight for as long as I can remember. I have focused on my weight during different times in my life, but I've never achieved long term success.
I've tried many different fad diets, not usually successful on those as I am not good at strict regimens or crazy elimination diets. Everytime I try to utilize exercise as my method of weight loss, I have always ended up gaining weight. I usually notice a change in my body but not my weight. Recently I have started a significant change in my physical activity, and as usual I have actually gained weight. I began fitness kickboxing about 2 months ago, and while I have yet to change my eating habits, I did think that I might still lose a couple pounds by participating in fitness kickboxing 3-5 days a week. But I now realize that this is not enough for my body.
I have also been trying to find a nutrition book that could point me in the right direction as an athlete that is also trying to lose weight. I have begun training for an obstacle race that I want to participate in next spring. All the books I have come across have focused on one or the other.
I am hoping that myfitnesspal will provide me with access to information that will make my new goals attainable.