I just recently learned Yi-Yield or Ferti-lome also sells calcium nitrate so if anyone else is looking for some you can use this site and it list stores in your area that carries their products. They might not have it on the shelf but they can order it.
It's listed under "Hi-Yield", "fertilizers" then "miscellaneous products"
https://www.fertilome.com/Products.a...4-47d6c2bff549