I'm so sorry for you loss.
Our first son passed away not long after his birth. I remember visiting my son's grave years ago, shortly after he passed away. He was buried in an area named "Baby Land," which had been purchased and donated to those in situations like us. An older man who was in his 50's or 60's saw us and came over. He had been visiting his daughter's grave, who had died before my wife and I were born. "It will always hurt," he said.
For us, it's been over 11 years now. I no longer get the random panic attacks while I'm working and my mind wanders. But it does still hurt.