Ok PLEASE HELP 10 POINTS!!!!!!!! PLEASE READ<?

ok im having a problem.. I want to start a diet but I keep on hearing diff things from people.. sum people say that if u drink more then 7 gles of water a day u will get fatter.. or if u drink 2 % milk it will help u loose weight??? or how about this 1.... if u eat fish or tuna fish it has alot of toxins and u will hold water weight, but then sum people said there doctor told them if they eat fish 4 times a week they will loose weight? I want to start a diet real bad and I think I can do it but people keep on telling me this or that & all.. the foods that I love that I cant get boerd with are.. tuna fish with/ tortia white corn chips.... or just grilled plain fish.. or chicken and water & water melon & all that stuff.. I can also drink a gl of milk if that works??? IM NOT LOOKING TO loose weight fast or anything I just want a diet thing that will make me losse sum weight over time.. like im 17 years old .. not that tall and 210 pounds.. I seem to go on a diet & do gud but then people tell me stuff so I stop & just get bigger.... LIKE IF I mess up my diet by eating a piece of chocolate I will tell my self that I messed up so im going to start 2 morrow so todays my last day to eat fatty foods so I eat alot but then dont go on a diet.. lol idk.. MY QUESTION IS CAN SUM 1 MAKE ME A DIET PLAN OF SUM THING OR TELL ME HOW MUCH FISH I CAN EAT OR IS EATING FISH EVERY DAY BAD 4 U? 10 POINTS THANKS!!!!!!