Try this for two weeks with no excursions or it won't work.
No dairy
No simple carbs
No processed foods of any kind
No bread
Strictly no deep fried foods
Yes pack your lunch every day.
No beer or wine
Limited spirits with mineral water or diet mixers are OK if you must drink.
Cut out sugar
No marinades.
In other words eat steak, salad, veggies, fish, eggs, chicken and any meat without sauces that are not freshly prepared.
Its a cave man diet, if it wasn't commonly eaten 150 years ago don't eat it. Do this for two weeks to allow time for your body to get rid of toxins and allergens. If you feel relief as I did you have either an allergy, a food disorder or you could be insulin resistant which creates inflamation in the sinuses and eustations. Give it a go it worked for me. Oh yes and go to the gym or do some sort of resistance exercise if you can.
After two years I now control any problems by controlling how much processed food I eat. The less the better. This two weeks will be bad but if you want to get better you have to give it a go!
SN