Fingers crossed. I'm shocked how long you've been left with severe symptoms, unable to work and not even given answers.
To be honest, i don't think the NHS has answers.... Working diagnosis when I was discharged from hospital at the end of July was "functional weakness". Which seems to mean "we don't know what's wrong, so can't give you any treatment".
Consultants have opinions, they may differ from the opinions of other consultants even though based on the same source information.
Don't let the lack of answers so far get you down, there is an answer out there, you just need to find the consultant(s) that can see it and unless it's extreme should be able to find them under NHS Scotland funding.
I'm assuming that your appointments with the consultant in Edinburgh is automatic and part of your NHS Fife care rather than because you've asked for a second opinon or for transfer to NHS Lothian's care.
So this is based on that:
NHS Fife are very limited in a number of areas as to the services they provide locally and contract other boards to provide services to them*; you're still under NHS Fife's care for the Edinburgh consultant.
If after working with the Edinburgh consultant you're still not happy with the diagnosis or case management, you can ask for either a second opinon (Which will be arranged by NHS Fife with a consultant elsewhere, probably Glasgow) or for the case to be transferred to another board.
The problem is if necessary both the second opinion and transfer routes takes time, effort and energy to argue for, the important bit to make clear to them is you want to work and you want to ride your bike if at all possible and you're not giving up until all routes are exhausted, many people give up and get retired due to ill health and sloth.
A friend had her ACL replacement transferred to NHS Lothian from NHS Tayside because she was unhappy with the consultant in Tayside (like proper unhappy, as far as she was concerned what was being proposed was batshit crazy experimental stuff and she wanted the tried and tested ACL graft that would allow her to ski again (Also helped she's medically trained))
* This is normal in Scotland, there's no point trying to recruit 14 shit hot Neurologists as you'll have 14 bored shit hot Neurologists looking for another post.
The structure is for the larger boards (Lothian, Glasgow, Grampian, Tayside) to cover most of the more specialized work on behalf of the smaller boards (A&A, Orkney, Shetland, Western Isles, Fife, Borders, D&G), with the medium sized boards (Highland, Forth Valley and Lanarkshire) doing a bit more than the smaller ones.
Even in the larger boards work is covered by Lothian and Glasgow for Tayside and Grampian, for example any cardiology work beyond fitting Stents is likely to go to Lothian and Glasgow no matter where you are. The cardiologist we work with is registered as a provider to Lothian, Fife and Tayside, and his private work and then there's his involvement in Digital and his own software development work... (Workaholic or what)
