Danielle, you have in your arsenal... the miracle of youth. Your metabolism is a machine right now and you will be able to get that 50 pounds off a lot easier now that you will at 30, 40, 50, etc. Oh it comes off then too, so you will have to work twice as hard then than if you start changing your ways now.
Also weight is quick, fast and easy to accumulate. Closing your eyes to it can lead to waking up further and further away from the goal you have.
*Weigh yourself once a week - not every day and don't skip weeks. This is important for 2reasons. Weight fluctuates all day long weighing yourself every day can lead to many dissapointments as the scale flip flops around not reflecting your true weight. Do it once a week and pick the same time of day (example, every wednesday morning when you first wake up).
Weighing yourself weekly will give you a more accurate look at your progress, but do not give up when you see fluctuations and KNOW you are sticking to plan. A lot of times weightloss slows or stops at first, some people even gain some weight while getting use to working out etc. Also if you ignore the scale , its so easy to put your mind in a place of denial which can lead to more and more weight gain.
*Be true to yourself - get a notebook, write down the date and your weight and hold yourself accountable for checking in.
*Do not go on crazy fad diets, take crazy diet pills, starve yourself or anything that will lead to you putting the weight back on PLUS many more pounds once you go back to a normal diet.
*Work out, exercise, walk, park from away from you intend to go. Move constantly. Everything you do is burning calories. If you haven't worked out in a while start with walking, 20 minutes a day and build up from there. Ellliptical machines are great for burning calories without stress to the joints and getting out of breath super easy. You should be doing some form of cardio, definitely.
*Keep track of what you eat every day, a food journal. Make the lowest calorie choices. Eat lots of fruits and vegetables and avoid greasy fried foods and foods high in sugar.
The thing is, at your age, you trully only have to work about half as hard as someone my age. Take advantage of that and get your body conditioned now and just enjoy the rewards of a lean healthy body the rest of your adulthood.
50 pounds is not too much to lose. Most dietians and doctors think a 1-2 pound weight loss per week is safe (be sure to check with your dr. to find out what is safe for you) if you stuck to your plan... you could safely be minus your 50 pounds in 6 months. Think about it. By new years eve of 2009 you can be a whole new you in the hottest dress available feeling healthy and proud.
That seems like so long off, too much trouble etc. Its not, new years eve of 2009 will roll around on the calender whether or not you change your habits, why not stick to your guns and know that this time you don't care that its going to take so long, you will be where you want to be soon enough
Good luck and never stop trying, never give up on yourself, know that you are worth it, know that you have the power within yourself to choose life over food, to choose exercise over bed and to choose strength instead of doubt.