As a former US-based teacher, I can honestly say I don't know a thing about teaching in Canada. But with that caveat...
The good thing is that here in the US (and I'm assuming Canada is the same) there are a lot
of alternative forms of education. After burning out on public school teaching (too bureaucratic and regimented IMO) and as my MS worsened, I did a number of alternative school settings -- and loved it. Everything from teaching GED classes for high school dropouts (fun as hell with motivated students) to teaching people forced to take classes because they were involved in the US' massive
So my suggestion would be to seek out alternative, out-of-the-box types of teaching situations.
My daughter, against my advice :), also went into teaching and was quite successful. But she's now taking some time off to focus on her own kids. She's been thrilled at doing some tutoring and teaching in-service classes for other teachers (anyone outside the district are often considered "experts" just because they're new/different and can offer different perspectives).
In short, think outside of the box -- education is a very wide field.
I use a cane right now but I would be too embarrassed/ashamed to use it ya school.
There often comes a time with MS that you can't "hide" your symptoms. You may have hit that point. (I've definitely hit that point.)
If so, I say "screw it." You have a legitimate disability. There's no sense or point in being ashamed about it -- it is what it is. For that I can only suggest it's time to change your thinking.
Changing thinking -- hey, you're a teacher, that should be easy!