Tracy, I hope you are feeling better soon.
By the time I was prescribed Mestinon I was in the same shape as you, sleeping most of the day and barely able to move...it took about a week to see improvement from the Mestinon, but once it started helping the change was amazing and at some point after I improved, I had to decrease my initial dose. I hope the Mestinon helps soon, but be patient, I suspect that Mestinon takes a little longer to start helping when your symptoms are severe.
And always remember that too much Mestinon is just as bad (worse in my opinion) that not enough.
Definitely talk to your doctor about dosage.
Thinking of you.