My first time on flight, i had this headache, my head felt like it was about to burst, is that a allergy or sickness?i'm flying out next week, what should i take for it to be better?

Headache from flying: Sounds suspicious for a sinus headache, caused by expansion of air in sinuses that is not able to escape due to congestion with sinus openings in nose swollen shut. Can be prevented by taking an oral nasal decongestant such as Sudafed, or use of a nasal decongestant spray. If you also had ear pain, it helps to chew gum or be eating something while ascending and descending in the flight.