Headache in the nerves of head of right.

I am having this headache from right ear to the top of the head in right side and from right eyes to the top of the head , can't bear more stress and unable to do my studies properly , easily get tired , sometimes my right eyebrow is also paining , I am taking nexito 10 mg from last 1 yr and L theanine tablets one in day and 1 at night , please do suggest something , how can I make my nervous system more tolerant to stress and studies ? I was given some CNS depressants in my cold drink once and I was unaware and once I was given a very cold ice cream to eat and then the problem started , my right side of head was numb and my memory was impaired and I am suffering this from last 2 yrs after this incident .