The guy asked for space. You sound like you were in each other’s pockets all the time. That itself can be overwhelming.
You have to be respectful of that. Whatever the reason. He doesn’t want to see you at the moment.
If you don’t respect him and stay away he will walk away permanently. If you do give him space he may get in touch and come back to you. If he doesn’t he would have left anyway so you lose nothing by staying away.
If he really did lose his dad he will likely be devastated. He knew him his whole life. He will need space and support from his family to get through this awful time. He’s grieving. He doesn’t need any drama.
If he didn’t lose his dad, and is lying to go on holiday with some woman or just to get away from your clingyness, you obviously need to dump him when you find out the truth as he doesn’t care about you.
So you need to keep away but find out the truth.
What’s his social media saying? Any clues there as to what’s going on?
If it was me I’d send him a message, if he doesn’t contact you on the day he said he would, to say “I’m so sorry about the death of your dad, I’m here if you need talk. I know you said you’d phone me today, but no pressure to reply to me just now. Just know I’m here and hoping you are ok at this sad time xxx”.
I’d leave it at that. Balls in his court.
If he doesn’t contact you within a further week you can try messaging him again to ask “How are you. Just wondering if you’re ok. Can you me a phone please”
If still nothing I’d leave it as he’s not that into you.
It’s hard but we’ve all been there with someone we want more than they want us. You can’t make someone love you. Sad but true.
Try and stay calm. See your friends. Stay busy. Take your mind off things. Exercise.