How to get over this fear of my loved ones dying?

I have extreme anxiety around my loved ones dying. I literally cry almost everyday thinking about it. I daydream about their funerals and going to the vet to put our pets down and everything. I think it stems from quite a few deaths in a short period of time (last one being February 2019) but still, I'm constantly on edge.

Especially my husband - I've been with him for 19 years and I just don't know what I would do without him, literally. It's not like we even have kids to keep me going.