Check out the wonderful B12 thread here: http://neurotalk.psychcentral.com/thread85103.html

When I first starting taking B12 it took about a week to notice the effects, but now that I am taking them regularly I notice an effect within an hour usually. I take one every morning before eating but also carry them around in my pocket if I am away from home. If I start feeling weak, I take a second or even third B12 vitamin during the day.

I am no expert in vitamins of course, but have heard that so many others on this forum have great results from this particular vitamin. It is not a cure for MG though, but definitely helpful even if you don't have MG.

About how you feel when you get up, I suspect this is variable with MG. In the past, my best times were in the morning after sleeping, but in recent months I feel best in the evening and weak in the morning. I have a difficult time getting out of bed and it takes me a while to get onto my feet. It might be that I have another issue, maybe with my thyroid but I haven't been to the doctor yet so I don't know.

My double vision is my least favorite thing. Recently I've been lucky only to have only slight double vision. In the past I had such bad double vision that I couldn't even see in front of me, my vision was just a swirl of colors. My vision sometimes shakes the way you described.

The brain fog is miserable. In general my brain fog has improved since taking vitamin B12 (nothing else seems to help the brain fog including the Mestinon I take for the MG). I still get brain fog when I am faced with a stressful situation or even decision to be made, as if my mind is shutting down telling me not to think too hard, I've wondered if it is some kind of protective measure to keep me from getting too stressed.

A diagnosis will certainly help so the doctor can find an appropriate treatment.

I noticed you said you have low vitamin D. Low vitamin D can cause a lot of problems, let me find the forum thread for you. I am no doctor of course, but I suggest taking vitamin D or, even better, be sure to get some sunshine which is the best way to get vitamin D and it is free. I do my best to get sunshine as often as possible and I do think it helps, nothing is a miracle cure for MG though. Vitamin D might help even if you don't have MG.

Here is the vitamin D thread, MrsD has collected some great information.
http://neurotalk.psychcentral.com/thread92116.html

I was thinking about your symptom list. It might be helpful to summarize your symptoms in a simple list. Try to think of a one or two word description for each symptom. It really helps when the doctor's office hands you the form that has only three lines or so to put all your symptoms down on. I don't think you should try to hide any symptoms from the neuro or other doctor, but do be as specific as possible. I do know what you mean about the list...I remember running out of room on the form at the neuro's office when I first went in before my diagnosis. I'd never had so many odd symptoms in my life.

I wish you well.