I am facing an severe headache only when I am in bus and can you please tell me a solution.

Question

That is part of motion sickness or travel sickness. 
Not being in the driver?s seat can contribute to motion sickness when you?re traveling by car. The driver of a car is less prone to motion sickness than a passenger, so drive whenever possible.
Avoid excessive alcohol, smoking, and foods or liquids that ?don?t agree with you? or make you feel unusually full
When traveling by car, it can sometimes help to keep your gaze fixed on the horizon or on a fixed point.
Expose yourself to short bursts of activities that cause symptoms, and then work up to longer periods.

Homoeopathy is excellent in such cases. 
For medication Consult online in private.

Tanmay Palsule · Accepted Answer

That is part of motion sickness or travel sickness. 
Not being in the driver?s seat can contribute to motion sickness when you?re traveling by car. The driver of a car is less prone to motion sickness than a passenger, so drive whenever possible.
Avoid excessive alcohol, smoking, and foods or liquids that ?don?t agree with you? or make you feel unusually full
When traveling by car, it can sometimes help to keep your gaze fixed on the horizon or on a fixed point.
Expose yourself to short bursts of activities that cause symptoms, and then work up to longer periods.

Homoeopathy is excellent in such cases. 
For medication Consult online in private.