Has he blocked me, unfriended me or has he deactivated or deleted his facebook account?

[Sophie]

Yes he has deactivated his account, if he had unfriended or blocked you, you either
a) would be able to see his account (if he'd simply unfriended)
or
b) wouldn't be able to see his account at all (if he'd blocked you)

So he's deactivated it, there's no way you can message him etc through facebook until (and if) he reactivates his account. Unfortunately, unless you can call him or have another social network or something that you can contact him through, then there is no way of accessing him.
Are you friends with any of his friends on Facebook who are near him and would be seeing him/ have his number? because if you do, maybe you could contact one of them and mention how important it is that you speak to him.

I really hope this works out for you, i've had a long distance boyfriend before and know that it's difficult. All the best!