Hello!
With the exception of the nausea and possibly the pain, it sounds like you have MG.
All of these you described are things I have had and are definite symptoms of MG: eyelid and mouth droop with heavy feeling, hand and arm and leg and neck weakness, choking, slurred and nasal speach, vision problems. As far as I know these are classic symptoms.
Pain and balance problems are not directly associated with MG, but can be caused by weak muscles. Often I strain my muscles because they are weak and then later they hurt, but this pain is not directly caused by MG.
Make a list of your symptoms to bring to the doctor.
There are lots of supportive people here. Let us know how you are doing.