While some folks with MS can experience nausea,
nausea can be a symptom of DOZENS...maybe HUNDREDS..of different disorders. I can't begin to list them all here. I tried googling MS and nausea and came up with it...but just googling nausea can bring up thousands of sites. I still think you need to eliminate the migraines as a cause for your problems before you start self-diagnosing that you have MS. Migraines can cause: black spots, colored spots, nausea and vomiting, weird sensititives to light, sensititivity to flourescent lighting...and on and on. Have you googled migraines to see all the variants that can occur with migraines, many of which don't even include a headache?
Sounds to me like the doctor was telling you what he was trying to eliminate-- MS -- and the negative MRI's coming back negative, when you have a history of migraines, should have indicated to him...and you...that migraines might be the cause of your problems, coupled and exacerbated by your anxiety over whether you have something more dire.
Why don't you do what the doctor recommended -- see a migraine specialist, see if you can get your migraines...and your anxiety..under control, and then see what symptoms might remain that can't be attributed to either disorder?
...I am not a doctor, nor health professional, and don't pretend to be one, here.....