Hi and welcome,
Based on your test results and symptoms it's highly unlikely to be caused by a neurological condition like MS, it actually sounds more suggestive of a peripheral nerve issue to me....
I dont know much about periodic limb movement disorder (PLMD) apart from there being an association with Diabetes and anemia (family issues) and its a sleep movement disorder that use to be called sleep myoclonus or nocturnal myoclonus.
Your PLMD might be causing you more disrupted sleep with your current higher level of anxiety, which in turn could be one of the reasons why your having some difficulty processing and concentrating at the moment, stress worry will always negatively effect your sleep quality too so it might be worth talking to someone about how being in medical limbo is impacting you.
The only other thoughts i had was to do with any medications you might be taking, most people dont consider the possibility of their sympotms being associated with a single or combiined medication, and a recomendation of getting updated blood and spinal tests done if its been awhile.
Hope that helps.........JJ
The main issue I'm focused on right now is visual sensory overload. It seems like there's too much going on for my brain to keep up like in the airport. My mind keeps going to MS but I pray its not.
Update - My MRI of my brain and C-spine on a 1.5T was clear. EMG/NCV was also clear. Still worried that I could have MS as my thighs continue to burn and feel like my visual processing is slow. Hopeful that 2 clean MRIs, 1 in 2013 and 1 in 2020 make it unlikely...
Your worrying about MS without anything to base your fears on so its just highly likely to be something that isn't a neurological condition like MS......you'd be much better off focusing on the fact that all your MS related diagnostic evidence since 2012 has been neurologically normal, your symptoms and symptom pattern isn't consistent so something like MS would likely not even be on your list of possible causes now.
I would suggest you consider seeking support and guidance from a therapist or psychologist about your years long health related anxiety, which will probably additionally help you become open minded about any possible issues that are being overlooked whilst you've been focusing on MS.
Sometimes there isn't anything you can pin these types of symptoms down too, so when your in medical limbo its usually recommend you make a point to get into your healthiest self ever ie improve your diet, increase your fitness level, priorities looking after your mental health, do something you've always wanted to do like learn to cook, finish your studies etc etc
hope that helps.......JJ