If you are an anxiety sufferer, people with anxiety often don't relax even when eating and drinking, so they often drink down more than they can swallow comfortably or don't properly chew their food. This is probably what's ailing you. MS isn't that common, and Googling symptoms will only cause you pain. But the only one who can diagnose you for certain is a doctor, and if you don't show any symptoms of what you're complaining about, you're probably going to get diagnosed with anxiety. Ever tried therapy and learning relaxation techniques?
There is an MS community you can post in about this too, go to the tool bar above and it is under communities.
There is something called gag memory which is anxiety based. IF you've choked, when you eat food similar to what you've choked on, your brain says "no" and you may gag. My son has this and we've worked through it slowly. There is a book called Food chaining which we used as a base for getting past it.
MS rarely presents with dysphagia and urinary problems, eye issues like blurry vision and general fatigue are more common. I suggest a cranial MRI to rule out MS (I don't know how does that work in Australia. Where I live, you can schedule an MRI for an equivalent of 120-150 AUD and pay another 100 or so to the neuro for interpreting the findings. She will prescribe something for anxiety if the MRI is clean)