Is it normal to experience thanatophobia and existential crisis after the death of a loved one?

Last week when I visited my 85 year-old maternal grandma, she suffered a stroke and after a few days she died in the hospital. It was deeply distressing to see her like that. I found it hard to accept that one moment I talked to her and she was, and then she wasn't. At some point in the past I lost my belief in afterlife so it feels depressing to know she is in a coffin and she doesn't know that she has ever been alive. A week later, sometimes I experience fears of suffering a stroke. Sometimes I wake up sweaty at night, thinking about my own mortality and the lack of meaning. I realised that I am not exactly fulfilled with my life because I strive to perform in a job which is not my calling, but I do it to be able to provide for a future family. However, I am single and sad about the fact that I can't find a suitable long-term partner.

Is it normal to experience thanatophobia and existential crisis after the death of a loved one?
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