<human>: Can you summarize the given text in a few sentences?

Ok so we're both 21, I've been in serious relationships before (almost got engaged) but he hasn't. We met a few years ago but didn't really talk and starting getting to know each other about 6 months ago. It was never intended to go anywhere because we currently live 250 miles apart (I'm away at university). We both fell for each other, though, and it's been great so far. 

Every so often he gets a bit funny and doesn't talk to me for a little bit but I just leave him to it without constantly bothering him and he'll eventually apologise and we're cool again. He works funny hours and is tired all the time so he falls asleep really early (8pm some nights) and often blames that. 

When I see him it's amazing, we have such a great time together and I really want to be with him. However, when we aren't together it seems like I don't exist sometimes ("out of sight, out of mind" comes to mind).

I try not to pester him much when he isn't talking to me, I'll text him once and maybe call an hour or so later and then leave it. The worst part is I know he doesn't ignore calls or texts when he's with me but seems to think that contact from me isn't important enough for a response.

He started Christmas morning and I've still not heard from him (almost 36h). I gave him around 24h with no contact and then text him to say hello and he didn't reply and when I tried calling an hour later he didn't answer. Am I being stupid or is this guy messing me around? Any guys have some invaluable insight to offer? Anyone out there in a relationship like this have anything to offer? Please help :(

I should also mention that I'm pretty sure he isn't cheating because he is strongly against cheating and I don't think he's a hypocrite.
<bot>: Bf hasn't spoken to me for 36h, not answering phone and I don't know what to do/think