Hi and welcome,
I'm currently experiencing a system glitch so i will do my best..
You've actually already been diagnosed (dx-d) with at least 3 of the medical conditions that are known to cause some of the same or similar symptoms as MS, "lupus, celiac, and Graves’ disease". Lupus is a condition that's said to be the greatest imitator but your more likely to find your answer is due to the multitude aspect of your combined medical conditions and less likely to be an additional neurological medical condition like MS, which from what you've said your test evidence has been inconsistent or not suggestive of. Keep in mind your normal brain MRI and your neurological clinical signs would not be over ruled by any LP results, and MS is a condition of the central nervous system so the majority of symptoms are not unique to MS...
Finding Pseudo-Papilledema vs. True-Papilledema
SVP - Pseudo Yes, True No
Hemorrhages - Pseudo No, True Yes
Retinal Striae - Pseudo No, True Yes
Enlarged BS - Pseudo No, True Yes
TVO - Pseudo No, True Yes
FluoroLeakage - Pseudo No, True Yes
Other Neuro - Pseudo No, True Yes
High Hypermet - Pseudo Yes, True No
https://cdn.ymaws.com/www.opsweb.org/resource/collection/4F618FFD-79A4-4204-8F5F-D47854209BCB/Tomsak2.pdf
"Papilledema is usually caused by the following:
Brain tumor or abscess
Head injury
Bleeding in the brain
Inflammation of the brain (encephalitis) or its tissue coverings (meningitis)
Idiopathic intracranial hypertension
Uncontrolled, life-threatening hypertension
These conditions typically result in papilledema in both eyes."
https://www.msdmanuals.com/en-au/home/eye-disorders/optic-nerve-disorders/papilledema
From my understanding, papilledema is the most common cause of swelling of the optic nerve but the similar yet different condition that's connected with MS would be Optic neuritis. Primary symptoms of papilledema are things like headaches or migraines, various visual issues, nausea, pulsating sounds, dizziness etc, i'm only 'vaguely' aware of idiopathic intracranial hypertension with papilledema being seen in women with thyroid issues.......True Papilledema is unlikely to be useful as a direction to consider though in the grand scheme of things since your initial dx of papilledema was revised to pseudo-papilledema, which has possibly happened because of the visible similarities they have are very difficult to distinguish...
"No treatment is needed for most causes of pseudopapilledema because they represent normal physiologic variants.
Diseases possibly associated with disc drusen may need treatment, such as subretinal neovascular membrane, central retinal vein occlusion, or ischemic optic neuropathy (largely to exclude giant cell arteritis in the appropriate age groups).
A minority of patients with disc drusen (16-22%) present with progressive visual loss. Field deterioration normally occurs over many years and is generally slow and unnoticed by patients. Dramatic field loss related to vascular complications, such as anterior ischemic optic neuropathy, can rarely occur. Unfortunately, no successful therapy is available at this time.
For patients who may suffer from glaucoma, it can be challenging to differentiate progressive glaucomatous field loss from field loss due to glaucoma. Estimation of the cup-to-disc ratio is also more challenging."
https://emedicine.medscape.com/article/1217393-treatment
Keep in mind though pseudo-papilledema is connected to SLE, Graves’ disease and thyroid conditions and if it is thought to have had more to do with dry eye's that's very commonly associated with celiac too so your visual issues are more likely to be connected to your known conditions than something else.
You said "A year ago a parathyroid adenoma was discovered and I had that removed." the timing of it is only 3 months prior to you saying all these other symptoms started so it's close enough to not be just a coincidence and probably worth looking into....... Parathyroid.com .....is a parathyroid informational site and might provide you with some ideas to look into.
Your symptoms are honestly more likely to be inter connected to what you already know, than to be due to an additional neurological condition like MS that your test evidence is pointing away from, and if your current treating physicians are not being helpful it would probably be in your best interest to get a second opinion and maybe provide you with in the least better treatment options.
I hope this helps........JJ