Cardio, sweat, and diet and not to forget the most under-talked about subject here mindset. Focus on your goals, hype yourself up knowing that you WILL achieve them if you want to (Anyone can) and discipline yourself in your head to achieve them and finally most important NEVER give-up learn from your mistakes and drive on like a hero from your new gained knowledge. Hop on an elliptical machine ed or eod for 30 minutes for a month and eat right measure and see your results that should be motivating for you to keep going. low fat high protien and screw Atkins you need some clean Carbs (But keep them under control) to get you going in the a.m and through your day. Drink lots of water while you are working out to keep hydrated and increase your vitamin C, take B6 and B12, take a multi-vitamin and flaxseed oil. Stay away from beer, nachos and finally television, video games, or any other lounge chair sports.
You will feel better, gain more confidence and most of all it is good for you!! Good luck and kick some ass!