You didn't post a lot of info but I going to make some assumptions. I'm 5'11 myself, and I was 253lbs about 5 years ago (at age 25). Today I'm clocking in around 187lbs and trying to lose the last few pounds to finish off the 6-pack. I didn't lose weight fast, but I kept with it, and eventually even my best friends didn't recognize me.
I'm not going to tell you what I did, but rather what I think you should do. I took a winding road to the knowledge I now have. You can shave years off if you go direct.
Step 1) Join a gym. Pay for 2 years in advance.
Step 2) Make a list of everything you eat in a week. Look it up. Figure out how many calories you eat and how much protein/carbs/fat is in your diet. This will take a hour a while, but you only have to do it one. You can get cell aps like LiveStrong too.
Step 3a) Make changes to your diet to cut calories, up your protien and lower your carbs. I STRONGLY don't recomend you try it right away, but eventually transition onto the Slow Carb diet or something similar. As Arnie once said: "Bread is death".
Step 3b) Up your fitness. Head to the gym a couple times a week, run, lift, swim, whatever. Again, ramp up - don't injure yourself going 4x per week now. Most serious lifters lift 4ish times per week doing only a few muscles each workout. Long term weights will up your metabolism more than long runs. Cardio is way better than TV though
My program now is working out almost everyday (heavy weights 4x/week, sprints 2x/week) and I eat according to the slow carb diet with 40% protein 40% carb and 20% fat, 5 small meals totalling about 2000 kcal / day. I don't do a cheat day, but I do cheat a bit here and there. After 5 years of low-carbing a potato hits me like a triple espresso, and I can't take a whole day of it. Even if I cheat, I don't top my calories budget. When I drink, it's scotch and vodka straight (1/3 the calories of beer).
There are pills out there that say they will help. I've have tried a few and not found any that are worth the cost. Fish oil might be, but I wouldn't stress about supplements until you get the diet and exercise right.
oh and one other piece of advice. Weigh yourself every morning, first thing. You will float up and down by 2 or 3 lbs so don't freak out if your up a few pounds from time to time. It's really only the long term trend that matters but doing it every day keep you accountable.
