The IMD is falling down on the job. She did do the blood work -- which, along with testing for clinical signs, and a spinal tap, are really all that CAN be done at this point...but doesn't seem to be willing or able to follow up. I'd be on the phone to both the IMD and the neuro, and press them to get him referred to the "big city clinic" -- which, given the length of time this is going on, and the bouncing around you're getting, would be a GOOD thing.
Or I see you do have a family doctor -- another plan is to get back to the family doctor, tell him/her about the run-around you've experienced, and ask him to serve as "gate-keeper" -- he can get on the phone, sort this out, make referrals to the "big city clinic" and get that on track.
Usually what happens there is - - because they have a variety of specialists there and "on call" -- referrals among them are quicker and more direct. Maybe they'll be able to sort out exactly what's going on. I don't know enough about the test results you offered to begin to give you any advice except that -- if they are abnormal -- that would not be typical for MS, but indeed typical of some metabolic or infectious disease going on somewhere, so the comments the one doctor made about a "virus" may not be far off the track.
Violet drops in on posts all the time to suggest that people with MS-like symptoms might have Lyme disease. That might actually be a good thing to follow up on, with your (husband? boyfriend?). There is a "first response" test that isn't always accurate -- but if it IS Lyme, may well indicate that. If not, you'd need to pursue a different, more definitive test. Has he been in/near woods at any time prior to these symptoms occurring? In the grass, at a park, anything where he might have come into contact with ticks?
At any rate, do keep on being persistent...but again, you might get back to your family doctor, tell him what's happening, and see if he's willing to go to bat for you. Good luck!