Plz Help!!Chronic Headache debilitating me?

Hi I'm 22..I'm suffering from Chronic Tension Headache from past 4 years..The headache remains throughout the day and has never ceased since past 4 years..Though I have been taking anti-depressants ( escitalopram etc.) for depression/ anxiety , as doctor had suggested since then, but they proved to be futile..Although I feel cured of depression n anxiety, but headache still persists,,I've tried all alternative therapies such as Psychotherapy, Ayurveda, Yoga, Accupresure, Homeopathy,,..but to no vail..I've flunked the same class 4 times due this problem, because constant headache doesn't allow me to study..I can't tolerate this anymore...plz help.,,Is there any permanent cure,,Is there any surgery for this Tension Headache,,.PLz Guide