I need to lose weight fast can you help me or suggest some way.?

Hey i need help losing weight ive tried tons of diets like atkins diet weight and watchers all sorts of em im wandering if this will help me lose weight i drink protein shakes in the mourning for breakfast and get on my Mountain bike and ride for 2 miles and do 20 sit ups for 4 hours i havent tried this yet but im willing to try because i need to lose weight and get healthy if you think this wont help me lose weight much please suggest somethinelsees that will work or maybe a working diet. please help!