I'm sorry you're having so many difficulties! It's good that you're seeing a neurologist.
Before your visit, try to sit down and list your various symptoms, leaving out any emotional stuff, anything that might sound like you're "whining", or "making things up". Just a straightforward list:
The buzzing sensation -- "I get this buzzing / electric shock sensation when I turn my head, sometimes. It seems to move through my shoulder and down through my legs." and leave it at that.
"My hands are numb; it feels like I'm wearing mittens, or gloves."
"I just experienced this episode of numbness up and down the whole left side of my body." (and describe -- briefly -- your trip to the ER, the tests that were run. And note how long this lasted.)
"My legs feel heavy, like I'm walking through mud."
and so on.
Then talk about the tests that were already run, and where the doctor needs to call to get them (if you don't have copies already, to give him).
As for the MRI -- lots of the folks here will tell you that early MRI's came back negative - -there were no signs of MS...but over time, lesions did develop and appear. So no, you can't say that because you had an MRI that was "negative" that you'd not have MS.
There are of course lots of things that can cause at least some of the symptions you describe, and it may take a long time -- measured sometimes in months and years -- for enough test results to come back "positive" for the doctor to make a diagnosis. But in the meantime you need to try to separate bad past treatment from doctors and others (it's just your bi-polar; it's all in your head; other dismissive comments) and be as calm and rational as you can as you deal with the neuro, in hopes that he'll indeed take you seriously and get to the bottom of your problems.
By the way, you wouldn't be the first person I know with bi-polar (or other psychiatric issue) whose psychiatrist went to bat for them, and got the other doctors to understand that the symptoms they were experiencing were indeed no psychological in nature but very real, concrete, identifyable problems. So if you get bounced back to your psych doctor again, you need to be clear with him, too.
Good luck with your neuro visit!
...I am not a doctor, nor health professional, and don't pretend to be one, here.....