I can sympathise - I have had this and it is very uncomfortable but a fairly simple operation may be able to fix it for you. If, like me, your sinus passages are relatively narrow, or the area into which they drain is small, an ENT surgeon can open them out for you by burning away surplus flesh. This opens up the passages so even if they do swell up, they are wide enough so they don't block.
This is considered non urgent by the NHS so you could end up waiting for a while to get seen by a consultant. It might be worth doing it privately if you can....you'll be out of hospital the next morning and back to normal in a few weeks.
PM me if you have any questions..
Hufty.