I'm sorry to hear about your new diagnosis, but glad they caught it early. Notice that Guillain ends with "ain" if you're going to search for more about it.
Two cases of Guillain-Barré out of 400 is much more than the 1-in-100,000 incidence in the general population. It's an area of study
, but tricky because of the small number of cases.
I hope your treatment is effective and it won't become the chronic type they call CIDP. Good luck.