Hi, The basic cause of all of your problems seems to be the deviated nasal septum. The repeated cold,nasal blockage, fever ,weakness,weight loss,hair fall -all are consequences of the septum. * Get yourself checked by an ENT specialist to know about it s management. Mild cases can be managed by decongestants,vapor inhalation,nasal spray,anti allergic pills. More severe cases need surgery (Septoplasty) * get yourself investigated & treated for allergies. * try to adapt ideal life style -including nutritious diet with vitamins /exercises/respiratory exercises,/sleep-& have a healthy & strong body with good resistance. Ths along with good hair care would avoid hair fall. Thanks.