Littlekitten, here's a suggestion that might help you with the swallowing problems when taking your Mestinon. See if your doctor will prescribe the liquid Mestinon, not to take the place of the pills, but in addition to the pills. Then when it's time for your dosage, or a little before, put a little of the liquid Mestinon under your tongue. It will be absorbed sublingually, and may give you that little bit extra relief from fatigue that will allow you to take your Mestinon without choking on it.
I used this method the one and only time I had a (near) crisis. In the ICU, I would put a little of my liquid Mestinon under the tongue every time I felt my breathing totally going. I would do it several times in between the doses of regular Mestinon, and it kept me from having to be intubated. The crisis, by the way, was brought on by my neuro trying me on steroids. Didn't work for me!!! Do you think yours will start you on the Pred again? Sounds like it did work for you, weight gain aside.
Hope you get a handle on this thing!
Hugs,