Welcome, BigFoot. MS and thyroid symptoms can be similar, but people here generally know only about MS. Did you know MedHelp has a thyroid forum as well?
http://www.medhelp.org/forums/Thyroid-Disorders/show/7t
I suggest you post your question there. (At the top the screen, under the Forums header you can find all the other topics too.)
I'm thinking, though, that if you had your thyroid destroyed, you technically no longer have Grave's disease, since you have no thyroid function at all. I'm also assuming you're taking a medication to compensate for that. So if I'm right, Grave's would not be causing your current symptoms. I don't know anything about your vision loss, but judging by the name of the condition you give, it sounds as if it's a blood vessel problem and not neurological. A neuro-ophthalmologist could give you better information on this, or a vascular specialist.
Protruding discs in your neck would not likely cause an unbalanced feeling, because this comes from brain issues.
Could you explain what you mean by being checked for MS? What tests were done? Have you seen a neurologist?
ess