Hi Stephanie and welcome to the Jaded Ladies!
I'm no expert, but I know it's really hard to lose weight by exercise alone. I have had a lot of success with Weight Watchers (although I seem to be at a plateau right now!) and would recommend it to you.
I have some friends who have lost with South Beach, and I know it is referred to as the "Healthy Atkins". Basically, though, you have to eat less than you need to survive, hence the loss. A pound is made up of 3500 calories, or 500 a day. If you normally eat 2000 calories, and you cut it back to 1500, you'd lose a pound a week. Forgive me if you already know this... anyway, I think you should keep track of your calories, keep exercising, and drink lots of water.
You don't mention your age or anything, but if you are a teen, make sure you get enough calcium. (Actually, that's good advice for any of us.) Try to pick foods that are good for you - fruits, veggies, lean meats.... you know the drill. Hop in at the Jaded Ladies chit chat if you'd like... we welcome you there!