You were spot on with the mother who called in about losing both of her children. As you say, the pain is excruciating at times...
I have also lost two children. I lost one son at age 17 from Glioblastoma, and I lost my daughter at the age of 35, from a pulmonary embolism; both on the exact same date but only 15 years apart.
Your advice is so valuable to all of us who have experienced this same hole in our hearts. I also was not able to return to work after our son died. I began volunteering, trying different opportunities until finding my fit at a local food bank. I get a good physical workout, and feed my soul at same time.