3 months of mild tension headache. will regular exercise and proper posture cure tension headache ? .. positive answer will relieve me from panicking,

Be careful: I wouldn't panic if all you have is headache. Headache is a very common problem, and almost always benign. For tension headaches you would benefit from muscle tension reduction techniques. Exercise is always good, but for some they often tense up during exercise and elevations in pulse and blood pressure may exacerbate the headache. Try massage, moist heat, meditation, etc.