Hi there...I can understand your concern. As you know few people have very high basic metabolism rate. It's difficult for them to gain muscle mass. Also from your diet, you are hardly taking any proteins, which is very essential to build muscle mass. So you need to start taking protein rich foods like soyabeans, pulses, vegetables, fruits. You can also visit a dietician. They will draw up a diet chart for you. Also try to avoid any protein supplements. They are not good for your health, especially long term.