I agree with Annie...find a neuro. Here are some ideas that might help you get a good one on the first try.

1) Contact your local Muscular Dystrophy chapter and see if they know a neuro in your general area that has dx'd (or specializes in) MG

2) Ask folks in this forum about neuros they may know of in your general area. (You can PM someone if they are in your area and you don't feel comfortable putting your general location on the board.)

3) Research centers and teaching hospitals - like Annie said - can be a good option. Besides the big ones, like Mayo...I know there are others in most major cities. Look them up on the web and see what they offer re: mg and other neuro dx's

4) Get emphatic with your GP. Mine didn't pay too much attention to my weakness complaint at first. But after a year, I pushed pretty hard and said we need to understand this because 'whatever it is' is getting worse and I'm sick of it messing with my life! (Funny aside,,,for the first time ever, I brought my husband with me for that apt. and he backed me up - even gave examples from his perspective. Viola! my GP was quick to respond with ideas and ordered a bunch of tests. Now it still took a year, a rhrumy, two neuros. and an oncolgist to zero in on a dx..but at least I finally got one!)

Don't give up. You know your body and you know something is not quite right. Even though it's hard to navigate the med system sometimes, pursue and persevere to get the answers so you can improve your quality of life.