Did you see a neuromuscular specialist that has a lot of experience with MG? Please see the MG of Australia link. They have an MG clinic in Sydney. If you do not feel your treatment is effective, I would try the MG clinic.
http://www.myasthenia.org.au/html/news.asp.

Unfortunately, MG is so rare that unless you go to a neuromuscular specialist that sees it all the time, patients often go undiagnosed or misdiagnosed.

I hope you have find your answers,
kathie