I posted about this a few weeks ago. The pain was so bad all my upper teeth were aching and I couldn’t eat. I ended up at the walk in centre out of hours in the worst pain of my life (no exaggeration, worse than wisdom tooth infections, surgery and childbirth!!) I begged for antibiotics and they refused, for a few reasons.
Anyway I was desperate so I tried everything suggested. If I were you...
Use nelimed wash. It isn’t nice, but it works. Use it once a day BEFORE then using a nasal spray. If you can get flixonase from the GP or nurse then this is the best as it’s an anti inflammatory. Rinsing the sinus first clears it well and means the spray can get where is needs.
Steam but WITH menthol crystals which are a few p over the counter from the chemist. Do this before the nasal since.
Take an expectorant (cough mix) which contains Guiasaneifen. This stuff increases and loosens mucus. That’s exactly what you want to thin out the heavy, stuck stuff in your sinuses.
Finally a don’t. Don’t use any kind of sinus tablets or decongestants or sprays. Sudafed etc. It dries up the mucus but doesn’t properly get rid and after 3 days use you get rebound sinusitis and you’ll be back where you started from.
Flixonase is your real friend. Go and get a prescription for that.
Good luck!