Have you tried Mestinon Timespan 180? It is usually taken at night just before you go to bed. It is a slow release mestinon and definitely helps me at night. If you feel like you have mucus in your throat, it may be because your swallowing muscles are too weak to get the mucus down. I tend to have this problem when my allergies are bad and I have been coughing a lot. I can't seem to get the mucus up or down and it can be a pretty serious problem. I do go to a pulmunologist and he prescribed me an at-home nebulizer with muco-mist to break up the mucous and it really helps.

I also use a c-pap and if I don't have it for some reason, I sleep in a recliner.

Hope you get this problem worked out! I can be a hassle.