Hi Mick,
I'm from Oz as well and have been lurking in here for a few months.
I'm sorry I can't help you with your question, but can only offer some sort of empathy.
It's an awful place to be in - limboland - and I hope you find some answers sooner rather than later.
As people in here have told me, a lot of diseases can mimic MS, so it's a process of elimination in diagnosing it/ruling it out.

Your body is telling you something's not right, so if you can, ease up on the training perhaps?
I wish you all the best.