Weight loss

So I have always been body shammed ever since I was little. I have never been confident of body. I was only talked to for being the 18 year old with Double D's. T.T In a couple of weeks will be my first time ever going to a beach with my boyfriend . I have a feeling he will finnaly propose to me (: I want to look my best for that special moment ! Any tips on how to lose weight quick ? I had tried everything from excersie to diets. No results .:/