5yo suddenly terrified of everything

[Pumpkinz]

Please tell me this is just a phase they grow out of? (Of course i know he wont still be doing it at 18 but its exhausting). My son is suddenly absolutely terrified of the dark, noises in the house, being on his own etc. I understand that kids get scared sometimes but even during the day, he often won't go in a different room without me because he is scared of monsters. I've no idea where it has come from. He doesn't watch YouTube, or anything age inappropriate that might have triggered it. Is there anything I can do to help him not be so scared?

I found that my son started having nightmares and these kind of monster talks after he watched Scooby doo, spider man and friends and afew other superhero cartoons. I know it sounds silly but they like these cartoons, have dreams about them and there imagination just works overdrive.
We just kept speaking to him about how they are just cartoons and it's not real. We would sit and watch some with him and laugh at the monsters so he felt relaxed about them rather than scared. Because in scooby doo they run from the monsters. My MIL suggested we stopped him from watching them but we didn't want to over shelter him from life. Lots of reassurance is key.

Maybe your child could be a little worried about the new school year and changes that may be coming, has this been going on for a long time? If not it could be the routine change of summer and the new school year pending.