Hope they have been able to give you some relief from neck pain. I just thought I would share a few pointers too that I have learnt along the way. Our neck (cervical spine) and our lower back (lumbar spine) are both sympathetic curves. Which means that when one moves, the other moves too. So not only should we avoid overarching our neck (when suffering from neck pain), but should also avoid overarching our lower back/lumbar spine. Because if you overarch your lower back, then that excessive back extension will automatically take your neck into an extension as well. It's just how the body moves.
Also, since everything in our body is interconnected, our necck pain can sometimes get worse with tight shoulders. So it might help to do some therputic exercises for the shoulders as well.
Hope that helps! :-)