Hello dear and welcome to the med help forum. Do you have risk factors for a heart ailment like obesity, smoking, hypertension, stress and hyperlipidemia. The pain of a heart attack is crushing pain, felt typically behind the breast bone in the centre or left, radiating to the left arm, jaw ,neck and face. There may be associated nausea, palpitations, sweating and shortness of breath along with the pain. You could be having a nerve compression of an exiting cervical nerve root in your neck causing this numbness in the arm. Consult a neurologist for clinical evaluation and MRI spine to assess. Wish you all the best.
I am not a medical professional but I do believe that sharp pains that start from shoulder and go into arm can be a signal of potential heart attack. But you have described numbness and that could be other things unrelated to heart. Short of breath could be another symptom.. It is always a good idea to check with your medical provider!
Have a good day!
Krystal