What is the best diet pill/supplement/thermogenic/etc to make me drop 15-25 pounds?

I'm 21, about 5'4 and weigh 139 pounds. I exercise atleast 3-4 days a week including cardio, weight training, circuits, stretching, and yoga. I eat very healthy and always have and I am a vegetarian, I eat small meals and eat the right amount of calories, I've tried to eat less calories, I've tried to eat more, I've tried to eat the average amount of calories, and nothing has helped. To look at me you wouldn't guess I weigh this much but am NOT muscular nor fat, I look like your average girl. So the muscle weighs more than fat doesn't fit with me. Although, my BMI says I'm normal I want to be around 115-125 or less if possible. Please suggest some supplements, thermogenics, diet pills, etc because I've tried all the "fat burn" foods and it doesn't do much at all. Please if you're going to comment rudely don't comment at all. Thank you I really could use some advice!