Whenever I eat or drink anything I feel heavy on the upper stomach and soon within half an hour I have to flush it out.I feel nausea in the morning sometimes with a headache.I am 55 years old female.

What does 'flush it out' mean?
Digestive problems are so varied that you really aren't going to find an answer online. Your entire history and current situation are factors, probably, not just age and gender. Are you on ANY medications, take any supplements, are you in menopause or past it, and so on... that's just for starters. Then you may need some tests, starting with basic blood work.