Hi Katy, amazing post what is your star sign you sound even more determined to soldier on than Possi :-)
I do at least half the things you do - yogurt and fruit for breakfast, also lots of water during the day.
No junk food at all, I prepare everything at home myself.
I totally gave up fizzy drinks and alcohol two years ago and yes this had made a big difference.
Morning stiffness and pain is the worst for me too.
Have you tried OMEGA 3?
For me it is as poweful as a daily NSAID however it started lowering my heart rate so I had to stop

Any other supplements you recommend?
I still don't understand why so many of you take probiotics ???
Have you considered starting a TNF-inhibitor.
I hope you have a mild disease and it subsides over time.