Suggest Remedy For Lack Of Weight Gain And Less Growth Of Beard And Chest Hair

Dear doctor, I am 23 year old male having height 167 cm and weight 49kg only.still i am looking like a 18 year old boy all changes except development of beards,hair in chest and body weight gain not happend with me.i am totally fed up with my physique.i checked for hyperthyrodism.but thyroidd level is ok.please give me advice to change my body physique