You won't see gains at 50grams of protein a day. Cut the junk food and start a clean cutting diet, 2500-2800 cals depending upon your activity level. Try and breakdown your daily food in 40/40/20 ratio. (40grams protein/40 grams carbs/ 20 grams protein) That said you should be getting around 250 grams of protein. A lot eh? Well theres the answer to you question, protein shakes. A good shake will give you 30grams WHEY protein, 200 cals, with lil/no fat or carbs. Also a good tasting proteinshake is amazing and will help you cut cravings and junk food.
Best Deal:
EAS 100% Whey Protein at that site, cheap, great tasting, 23 g protein per serving (6lbs worth of servings), 120 calories, only like $23.00. Mix it with 8 ounces skim milk, throw in ice cube, one scoop and blend. (not trying to sell this stuff either, just what I have found to be the best)