Welcome in H.C.M.
I have gone through your query regarding constant cough, hoarseness
in voice,cold ache in left arm and heaviness in neck.
Since 9 weeks had passed in your present disease therefore you should consult ENT specialist
to rule out causes of prolong cough like-
(a) Chronic laryngitis
(b) Vocal nodule & growth on vocal cords.
(d) Diseases of lungs as- bronchitis
, asthma, chronic pulmonary infective diseases
(e) C.H.F. - though it is to be diagnose by cardiologist but any doctor may put it in suspicion by listening basal crepts on auscultation.
So I think a thorough examination and relevant investigations are now became necessary as your cough and hoarseness is there for quite long time.