Mixed symptoms acute onset

Hi all,

Wanted to see if anyone has had a similar experience to me.

About 4 months ago I woke up one day with severe fatigue - the only thing I could liken it to was the exhaustion I felt when I had glandular fever as a teen. It lasted about a week and then bam - I woke up one morning with joint pain pretty much all over. I was hobbling around like a 90 year old. It also caused weirdly disproportionate muscle pain - simple tasks like putting washing on the line would make me feel as though I'd lifted 10000kgs at the gym when I woke up the next day.

It gradually improved, but about 2 months ago it plateaued out, and I have a constant ache in my ankles and one wrist.

I've had bloodwork done for just about everything - to look at it you'd think I'm perfectly healthy. They checked all the standard inflammatory stuff (CCP, RF, ESR, various vitamins, FBC, the list goes on), and also viral causes (ross river, barmah) and also tummy bugs (camplyobacter, yersinia, salmonella etc), but everything came back normal.

I had my first rhuematologist appointment a few days ago and she seemed a tad perplexed. I don't have morning stiffness - it's actually the opposite, the more I am on my feet the worse it gets, it kind of goes from a stabby and achy ankle pain and spreads up to my knees, and then my hips.
I have minor swelling at night (if I've spent too long on my feet). I have absolutely no other symptoms, just ankles that are making my life very difficult.

I'd like to add I am a fit 27 year old female, I have no relatives with any sort of autoimmune diseases, and no history of any ongoing pain (joint or otherwise). I haven't had any sort of gastro or illness beforehand either, I had a weak flu/cold maybe three weeks before but nothing tummy related. I have no pain in any of my small joints - it's basically my ankles giving me grief.

Has anyone had mixed signals like this? The rhuematologist said there's inflammatory and non-inflammatory arthritis, but what I'm describing appears to not fit either. She's looking into early stages of seronegative RA as a possibility - is there anyone here who had an acute onset of RA (particularly seronegative)? What was your experience of it?