What Causes Discomfort Behind Uvula And Blood In Saliva?

I feel a long, thin, sharp foreign body under the skin / in the soft tissues of the neck/throat region retained for several months. I have consulted a doctor who sent me for an X-ray, which didn`t show anything. Subsequently, I also saw another doctor, who sent for a CT scan, but it also didn`t show anything.I can feel the object sliding slightly time to time near back of the throat and upper back side (behind) Uvula. In past few weeks i was spitting blood too which is a sign that there is something inside (scratching and damaging tissues etc). I feel pain and sourness in the throat area.The pressure of the object under the skin can be felt all the time 24 hrs a day, except when sleeping.I usually feel least pressure or discomfort when in lying down position on the back (e.g. after a night’s sleep). I can often feel it shift position/slide slightly in the tissues.All ENT specialist i have consulted so far are saying that there is nothing inside they have also done endoscopy via nose and mouth. but they told me that everything is fine and i should consult mental dr.But i am feeling it and i am in pain and the burning effect (Sore) is there so i am not crazy or having mental disorder.I would appreciate any advice and hope for a reply. Thank you very much.