Hi there.
I welcome you to healthcaremagic.
I understand your problem.The symptom you described is most likely of acute 
torticollis,in which the person's head tilts towards one side.They may experience deviation of the eyes and protrusion of the tongue,
shoulder pain, back pain, headache, 
neck cramps, muscle tightness, or burning sensations. too.This can be caused due to several reasons like trauma to the neck or spine,infection of head and neck,infections of the sinuses, ears, mastoids, jaw, teeth, or scalp,certain drugs of abuse such as cocaine,amphetmine or any other neuroleptic drugs.
Secondly it might be due to weakening of  nerve or 
chronic bleeding in brain due to some trauma long ago.I would have suggested an Xray Neck and a CT scan head to come to a diagnosis.Please 
seek medical help.
Hope my explanation helped.