Alex responded to my messages. He said his Dad died last week and he's been by himself, not wanting to talk.
I apologised and said he should have told me.
I'm taking a step back because either way he didn't tell me and I jumped to thinking the worst and letting my insecurities get the better so it says it all about us. I have had a cry though. What a nasty witch I am.
You're not nasty at all. You weren't to know. Respect and communication is important in all relationships, whether that's romantic or platonic or family.
You were chatting for a few months, is that right? So you're involved to some extent, and by that point you'd hope he'd be able to share these things with you. I can't tell someone what to do when a parent dies, everyone handles it differently...but at the same time, I do think you need to face up to things and send a quick message to people who are in your circle to say "hey, just letting you know my dad has passed, I'm coping but will need a bit of space". I remember watching my dad phoning up everyone who needed to know when his dad died and was taken aback at how well he handled it - certainly didn't hide away for weeks avoiding it.
Probably best to leave it for now and see how it goes.