Hello and welcome
It might be a good idea to have a look at the 2011 McDonald criteria for diagnosing MS to get an idea how close you might be to getting a diagnosis. The full paper is free to download, but a bit tricky to follow if you’re a novice to neurology so wikipedia or something similar might be a good starting place.
In a nutshell, the two main criteria for relapsing remitting MS (RRMS) are that there have been at least two attacks and that there are at least two areas of the nervous system that have been affected (normally demonstrated by having lesions in two different places on MRI that are typical of MS). Primary progressive MS (PPMS) requires at least a year of worsening symptoms and two of the following three: at least two spinal lesions, at least one brain lesion in a place typical of MS, a positive lumbar puncture.
What happens at your next appointment will probably depend on what the referral letter says and how typical your symptoms, history and MRI are of MS. I’d recommend being ready to (concisely!) summarise your symptoms and history and to make sure to take a list along of any questions you have and any symptoms you need help with. I’d also recommend taking someone with you - an extra pair of eyes and ears can come in very handy!
Unfortunately there are all too few MS specialists so it can take far too long to see one, but you could always tell the hospital that you’ll take a cancellation on short notice, if you can of course - you never know, it might get you seen sooner. It would also be worthwhile asking your GP for a referral to a neurophysio to see if they can help with your balance (and anything else) - no point in waiting for the MS specialist when a GP can refer you now.
I hope you get some answers soon. Let us know?