*TW death and existential thoughts*

I recently lost one of my closest friends unexpectedly and for the last few days I am experiencing this constant sense of dread and unrelenting thoughts about existence and death. I feel sick and sad and anxious about these thoughts and I'm sitting around spiralling and thinking myself into a hole by thinking about death so much. I need to just stop thinking about it because no amount of thinking about it will bring me comfort with the idea of death but I seriously cannot stop the racing thoughts. I've dealt with these thoughts in the past and have gone through phases where I'm seriously depressed and constantly distracted and upset by these thoughts. The feeling of existential dread just hangs over me no matter what I'm doing during these phases and usually the only thing that brings me out of it is to be consistently distracted and eventually I forget about it and won't be upset about it anymore until something triggers those thoughts again. 

This time, it's the worst it's ever been. I cannot distract myself nearly as well because I am stuck at home because of covid. I can't even watch shows or anything because even the slightest reference to death, eternity, afterlife or even talk of the past and  history sometimes will trigger the spiral. I don't even want to talk out loud about my thoughts to my loved ones because I don't want to make them spiral about it and get anxious about it as well. This is the first loss I have ever experienced as an adult but when I was a very young child and my grandfather passed, I remember experiencing nearly this same thing except I didn't fully understand it. 


Does anyone have any advice on dealing with this type of anxiety and these thoughts? I am on multiple meds, do therapy etc. I am not religious and although I wish I could be (I think having faith would be so much more comforting), I don't think I could make myself believe in something that can't be proven with science. As a child I remember trying to just dismiss the thoughts and fears of death by telling myself "well reincarnation is probably real" and eternity then sounded much less scary and death was much less intimidating, but now I can't force myself to believe things without facts and science anymore :( 


any words of comfort on this topic are very very welcomed