Is your BMI within the required RAF range? I was just within it but I now undergo a new eating plan and workout schedule, had my own personal trainer too. If you want to bulk there is plenty of information out there but apparently you need to eat around 3000 calories a day to gain one pound a week. Easy way to hit this target is whole milk with pure mass gainers, calorie dense foods and small meals like couscous, tuna, nuts etc. I also go to the gym 4-5 days a week, with two upper and two lower workouts, plus running each day.