Thanks for writing to H.C.M. regarding your query.
I have gone through your query and as you said that you always feels saliva in mouth and even after try to sallow it your throat remains filled with saliva. You have pain over back around shoulder blades.
Your problems indicates us that you are suffering from Dysphagia. Here abnormalities may be at the base of tongue, Pharynx or in esophagus
To confirm it thorough examination of throat and upper G.I. Endoscopy
is must to find out the pathology. As soon as the abnormality is identified proper treatment may be planed.