Going by your narration i think you are more of an anxious person or you might be facing certain odd circumstances like great pressure at work or enhancing your performance or may be some emotional disturbances, all these causes might be the reason for the present set of symptoms you are having.
Gastric derangement and flatulence
or gas are found to be causing sick feeling and headaches
and at times anxiety
feeling also with discomfort in chest, nausea
etc. Your case seems to be more of anxiety and less of pathology so we need to identify the things bothering you and deduce the suitable measures to neutralize them.
I would suggest you to see a life style expert and a Homoeopathic Physician because Homoeopathy takes into account all your disorders and mental condition. For the time being you can do the following:
1. Try to go for a brisk for 30 minutes, some stretching, or some cycling or swimming etc. because physical exertion is the only natural solution to beat the stress
2. Avoid taking heavy diet consisting of more of fats and fried.
3. drink lots of water.
4. cut down liquor if you are taking it.
5. only white meat and no red meat.
6. do not take tea/coffee/beer/whiskey etc empty stomach, take half a glass of water before tea or coffee with a few biscuits and in case of liquor you should not be empty stomach for more than atleast 4 hours before your drinks. do have non fried snacks with your drinks like salads.
7. do the breathing exercise
in guidance of some instructor or you can opt for yoga also.
8. try to identify the cause of your stress if its emotional at home or work related at office. you need to make suitable changes in your time table at office to meet your deadlines and do not try to be unrealistic afterall Rome was not built in a day.
9. do take short breaks at work and do use your holidays to pamper you with short tripps and some good company if you do not have good company do participate in some community work.
10 at top of all try to be confident of yourself and accept things as they happen only then you could deal with them.
Feel free to ask any other queries you have
Wish you a speedy recovery to health