The ideal solution is to seek a dermatologist who can assess, examine and diagnose exactly what is going and treat accordingly. Dark circles can be hereditary, dietary and also a part of a more complex pathology, it would be of great help if you seek a proper consultation with a skin specialist to help with all your concerns. As for hair fall, first and foremost don't stress, it can be taken care of and with some counseling and treatment even reversed to some degree.
Next Steps
consult a specialist or online consultation with pictures.