I'm worried about my friend. How do I keep myself calm until I hear from him?

I’m a little worried that something may have happened to one of my really good friends and it’s starting to make me incredibly anxious.

We normally text each other throughout the day and today was no exception. My last message to him was around 1:30pm (EST), before I had to leave for work, and it’s now 3:20am. Since we live in different countries, we use a free messaging application which let’s you know the status of the message (Sent, Delivered, or Read).

It’s not like him to go this long without writing back. Normally I wouldn’t worry about it if he’d read the message but didn’t reply. However, it just says that the message was delivered but never read. We haven’t had any disagreements or anything of the sorts that could explain him not wanting to talk to me so I can’t help but think of worst-case scenarios.

I have no reason to think that something bad happened, but that’s where my mind keeps going.

There’s really nothing I can do at this moment other than wait until he writes back but I am seriously worried. How do I keep myself calm until I can talk to him again?

Just to clarify: I’m not at all upset that he may have read and not replied to my message; my concern is that, since it says that the message was never read, something may have happened to prevent him from getting to his phone.

Thank you in advance!!!