How to deal with a fear infested husband

Ive been with my husband for 13 years now. My husband is constantly watching the news and has so much fear over this and that. He says its because he is smart and knows whats going on and i get all that but it seems he is on the extreme side of the news. Every year he is talking about civil war breaking out in America, world war 3, all types of horrible things which doesnt happen. He has even filled our food supply in fear of war, got guns etc. im so tired of it. He stresses about that. I dont know how to deal with it. Honestly if i knew he was like this when we were dating i wouldnt have gotten married. I love him but he is so depressing, there is not one positive thing that comes out of my husband’s mouth. His reality is the world is ending the last 13 yrs we have been together. And its hard to build with someone like that because of how they think.