Suggest Treatment For Severe Dizziness And Twitching Of The Eye
Inner ear issue more likely
Detailed Answer:
I read your question carefully and I understand your concern.
Judging from that description of vertigo (spinning sensation), nausea, nystagmus (eye twitches), exacerbated by change in position I would say that the most likely possibility is an inner ear issue. The inner ear apart from hearing function is very much involved in balance so any condition involving it or the nerve exiting from it(like viral infections, Meniere's syndrome etc) may cause the above mentioned symptoms. Vertigo, nausea and vomiting which are augmented by changes in head position are typical. In this case the most used over the counter medication to alleviate the symptoms (which might take a few weeks to gradually improve) include meclizine or betahistine.
The other possibility which can be threatening and must be considered is stroke. Stroke in the posterior areas of the brain may also manifest with such symptoms and should be considered in particular in a diabetic individual as diabetes increases risk for stroke. Usually stroke has some added neurological symptoms like prominent headache, slurred speech, difficulty swallowing, double vision or vision loss, numbness or weakness of half of the face or body, difficulty coordinating movements etc. So I do not want you to panic, stroke is unlikely in the absence of any such symptoms. However if easily accessible a visit from your primary physician or even in the ER would be prudent to make sure there aren't any neurological signs you might have not noticed which would indicate stroke.
I remain at your disposal for other questions.