Should I go on a diet? Get a gastric byp or lapband surgery? I am 18, and I weigh 354 pounds.?

Okay, I weight alot. I'm asking this as a young girl who is tired of looking like the way she is, and who wants to desperately improve my health. I've tried many diets. I've done so many "quick fixes". Please do not take this lightheartedly, or make fun of me. I am just tired, and I want to know if it's health for me to get surgery, or maybe just try a diet with a personal trainer? I have many friends and I am very happy on the inside, but it's the outside that continuously brings me down. SO what should I do? and how should I do it?