Hi there...if you feel like you are suffering from depression, why would you visit a physician or neurologist. You need a psychiatrist. They are best people to deal such conditions. There can many causes for depression, including personality disorder, emotional triggers, medications. Also how low is your blood pressure? Because some people especially who are athletic, normally have low blood pressure around 100/60 to 120/80. So kindly consult a nearby psychiatrist for further evaluation. Also it always good if a family member can accompany you to a psychiatrist. If possible Try relaxation measures yoga, meditation, brisk walking daily.