I usually just hit the hotel bar once I get to my overnight, that get's rid of the headache. No, really, you probably should go see and EN
&T doctor. You may have an ear problem and could be close to blowing an eardrum or two. It happenened to my roommate, but she immediately went to a doctor and they gave her whatever it was she needed. The drawback was she wasn't able to fly for 6 weeks, but her eardrums sealed back up and she was back to flying with no problems. The only other thing I can think of is, if you feel sick before your trip, don't fly. I'm guilty of still flying, but we have to make money. If you are a little older in age and you aren't feeling well, take the losses, call in sick, go to the doctor, and you'll make the money a later day and be back to work that much faster. As cold and heartless as the airline industry seems to be, usually your immediate boss should understand and not want you to fly. Of course I say this now and never followed that advise, so I always suffered. I know it sucks to use sick days when you could turn them into vacation days, but in the long run, you'll be better off.
EMB145 F/A, F/E, J41 F/A, F/E, because my wife clipped my wings, armchair captain