It's all very scary at first. It was for all of us (I feel comfortable grouping us all together for that!). And it's hard to wait....and wait.....and wait. I'm so glad they moved your appointment up so you can get some answers.
MS isn't easy to diagnose. It's more of an elimination of other conditions to narrow it down to MS. And that can take some time. It sounds like you've got a good doctor who's working to figure this out. It's still hard to wait, though.
When I was waiting for my diagnosis I actually thought I had a brain tumor. My most prevalent symptom was severe double vision. And it lasted for about six months!

I did alot of self-diagnosing on the Internet and let me just say that is NOT a good idea! By the time I heard the Neuro say "you have MS" I was thrilled! He was a little taken aback by my reaction but when you're convinced you have a brain tumor hearing "you have MS" was music to my ears!
I hope you'll post again after your appointment and let us know what the doctor said. You're going to be fine......