hi there, your symptoms are suggestive of pain caused due to keeping your hand in a certain posture for a long time and due to unaccustomed use. The neck pain
is also a sign of bad posture and strain of holding the baby for a long time in one arm. Prolonged pressure on the arm may be causing hypoxia
of the nerve
roots which is causing the tingling sensation
. Before you go to any conclusions you try changing the posture in which you handle the baby and try changing arms often. Also it would be good if you could hold the baby only while feeding or nursing and otherwise keep him close to you on a rocker. A few neck massages and some physiotherapy
to the arm and neck should relieve you of the problem.Try sleeping on your back or alternater the side rather than sleep on one side due to the baby,Or you could also transfer the baby to the crib so that you have a comfortable posture while sleeping. If these simple measures do not help and you still experiencing these symptoms then you can get an MRI
of the shoulder done to rule out any organic cause and get treatment accordingly. Take care, Your health is as improtant as the baby's, Do not neglect yourself.