I feel you! I used to be 5'2 and 180 at one point, so it's pretty similar. Do not take dieting pills, it's a waste of time. You have to lose weight through real exercise and cutting back. I know this diet called Weight Watchers, and it really worked for me but if you don't want a diet and you just want to make your own sort of plan then I recommend you do at least half an hour of exercise everyday, have at least one fruit as a snack in replacement of what you would normally have, and the thing that helps the most is no carbs for dinner. You gain SO much weight from carbs at dinner, it's not even funny! By doing this, I am not 5'4 and a half an 150 pounds. I used to be really upset with myself but there's no explanation how confident and happy you get when you lose weight. Good luck, hun! :)
Set a realistic goal to lose 2lbs in a week through a strict diet and exercise. Increase the activity level throughout your day i.e. take the stairs instead of walking; do aerobic exercises which include swimming and running. You can also go to the gym. Cut down on your calorie intake and take more fiber filled foods which have few calories and will make you full for longer.