Losing weight fast

Hey girls,
​I really really really want my bikin body back.  Currently slightly fat around the waste.  I want it gone so i dont have to stuck in my stomach any more.  In 3 weeks and 5 days, ill be at the beach and i would like to wear my new bikini.  What are some ways i can quiclly burn the weight and tone my stomach.  Any help is great!!