One of the strangest things about losing weight is being able to understand that eating barely anything a day is far worse then eating 6 small meals a day. What happens when you don't keep that metabolism going is that your body goes into "starvation mode" and it holds on to that precious fat for energy, and starts using important things like muscle to live off of.
You said that you enjoy pizza and doritos, well, those days need to stop
. All those extra Carbs are what is keeping that layer of fat going. You should speak to your doctor or a nutritionist about going on a diet. They will be able to figure your basal metabolic rate and figure out how many calories you will need to eat a day in order to start a caloric deficit, which will shed that weight off naturally and permanantly. My guess is that you will be put on a 2800ish calorie diet, which you will have to learn to start reading the labels on things and figure out what you should be eating and what you shouldn't be eating.
If you were to limit all the carbs that you eat by restricting them to only morning and afternoon (making sure that you get no carbs for dinner untill the next morning)... that along with drinking a lot of water a day (shoot for a gallon if possible) and kicking the sodas, doritos, and other crap you are putting into your belly and getting a little cardio exercise in, I would say you will lose about 10 + lbs in the first 2 weeks. Keep it up, and you will be looking great and like a completely new person by next summer when its time to walk around without a shirt again.
If you get on a plan, make sure to document all of your progress. That is very motivational in keeping at it, because it ain't easy. Best of luck to you, and post about your weight loss weekly!