first no pills, at your age you just need good old fashion hard work. You have to remember this stuff doesnt happen over night, it takes time. You need to start making this a life style and set goals for yourself.

Ive never like riding a bike for cardio, try running, i like running cause when your run it keeps your abs tight the hole time. When your sitting on a bike your abs are lose. Try different things

How long have you been dieting, you have to remember that most good diets if done right will take about 12 to 16 weeks to complete.

Why dont you post your diet so we al can see what your eating