Try to take deep breaths.

I usually inhale slowly, then hold it for 4 seconds, and exhale slowly, then repeat it until I'm calmer.

The headache won't go away, but this'll keep it from worsening.

Oh, and if you like drawing, I recommend drawing flowers (or anything) and write how you're feeling in the sky or an empty space.' Try to go as deep as possible and use the most accurate word, then think of why you feel that way, and search for the good parts in it.