Dear Divya, First of all, pls dont lose your heart and confidence because of your weight. It is important to be a good human being, and i am sure you are a gem. Now as for your weight issue, look dear, you dont just need to put on weight, you need to put on healthy weight. Start eating a high protein, high complex carb diet like eat milk and milk products, soy products, egg whites, chicken, pulses (dals), multigrain flour with jowar, bajra, ragi and oats, fruits and dry fruits. Exercise 5 times a week, 30 mins and do weights and resistence training more tahn cardio exercises, so that you put on right amount of weight at right places. It will be a long journey but dont worry. And all along, for morale boosting, pursue your hobby as well. It is also advisable to meet your doctor and get your thyroid, vit.b12, folate and iron studies done. Meet a psychiatrist to rule out any issues like anorexia. Get well soon!