Hi everyone, first post here, I'm not sure whether this is a mental illness or not but here goes.

Ever since I was a kid my dad has always warned me about all sorts of dangers, and kinda have always over exaggerated a lot of things. Now whenever I cannot contact a friend or family member that usually replies very quickly, I get paranoid that something bad has happened, especially so if I know I am in a position to go to their aid. 

I feel like this is an irrational fear because I live in a very safe city, you can walk around alone at 2 in the morning and no harm would come to you.

But I still can't shake the feeling that something bad may happen, and it really gets in the way of me going about my day until I'm able to re-establish contact.

Is there anything I can do to help mitigate this? Am I just overly worried or stressed? (There isn't really any irl things happening that adds stress for me so I'm not under any high stress environment).

Thanks in advance to all that help.

Tldr: I get paranoid and fear for bad things when I can't contact people I'm close to, even though it's irrational.