I don't feel that cyproheptadine is very anti-cholinergic, have you tried Benadryl (DPH) or Scopolamine patchs. Do your symptoms get worse when you are exposed to tobacco or using nicotine patchs?
Benadryl has no effect and not taken scopolamine or nicotine patches.
Another thing I forgot to say is I get myoclonus quite a bit as well