So sorry you are having so many symptoms. I've been there, still go there from time to time.

It's my understanding that Timespans work about 8 hours or so, which is closer to what you've learned as well. The saliva issue can be caused from both too much or too little mestinon, so it may take a while to find a balance.

As for when you can expect symptoms to improve, that is impossible to say. I am pretty certain you are not properly medicated. The pred dosage is relatively small, the mestinon dosage too low and almost everyone requires polypharmacy to get relief when symptoms are so troubling. It will take time to find a combo that provides relief. In the meantime, the gym is probably not the best place for you, even if you aren't doing big workouts.

Take care.