Hi and welcome to HCM! Thanks for posting your query here. Heaviness at the back of the neck can be caused by increased BP or pressure on the nerves in the cervical region. As the x-rays are clear and BP charting is near normal you can opt for a CT scan. This gives a detailed study about any nerve compression which is causing the symptom-cervical spondylosis. If this is ruled out please check the BP regularly and if the same value continues try using a low dose antihypertensive. Because some patients are very sensitive to the minimal changes in the pressure. Acidity will give a referred pain in the low back and to the shoulder blades. So this can be ruled out Hope this is helpful to you. Regards