zdanie

Cześć :)

I am concerned that we won't be allowed to leave the country.
Obawiam się, że nie będzie nam wolno opuszczać kraju.

Czy zdanie jest ok ?

raczej 'I am worried'

affraid

affraid
afraid

I am concerned we might not be allowed to leave the country. (Not being allowed to leave the country is your concern; e.g. being unable to cross the border)

I am afraid/worried/concerned we won't be allowed… implications of not being allowed to leave the country are your concern.

I am afraid/worried/concerned you're looking for nuances that aren't there, Mr Janski.

The two sentences mean the same, with might being more tentative than won't.

what follows 'concerned' or "worried' refers to a fact.
what follows 'afraid' refers to a possibility (not fact)
Janski's use of might/won't reflects this interpretation, but he wasn't able to verbalise his thoughts in a description. He was wrong about 'afraid' though

It also seems that 'concerned/worried' would be stressed and the description of a fact that follows is thematic, i.e. it has been introduced earlier on in the discourse.
What follows 'afraid' is rhematic and would receive sentence stress.
I don't think 'afraid' could be stressed and so introduce a fact. To me, it could only be stressed in a lexical contrast setting, e.g. 'I am afraid, not exasperated'

Define 'fact' :-). A couple of sentences from the "news":

I begin every season worried that we won't be able to equal the previous season.
I'm not worried that we won't be able to handle the situation.
I am worried that we won't be prepared!

In each sentence, what the speaker is worried about is a future scenario that has every chance of happening, so it's more of a possibility than a fact.

Verbs, as a rule, are content words and carry a meaning. Some kind of fear or fright should underlie a feeling of being afraid.

I am afraid of the dark, venomous snakes, death,… but of being disallowed to leave the country?

Miss Prissy, a hypocrite who feigns concern for humankind and pretends to be a caring person, might say "I am afraid you won't pass the test." It doesn't say Miss Prissy is fearful of anything in any way. (She is just being herself). Switching the order, "You won't pass the test, I am afraid," would change little as far as Miss Prissy's attitude towards me is concerned. Perhaps—just perhaps—she would mean to break the news to me, and her I am afraid might be an afterthought. ("Unfortunately" from her would be too much.)

Being afraid doesn't mean being concerned or worried. Being afraid doesn't convey a feeling of regret or unhappiness either, and I don't care what dictionaries want you to think.

@zielonosiwy
coming back to the original posting
'obawiam się, że' is a prediction of undesirable developments and is therefore incompatible with 'concerned', which expresses one's emotional state related to such future developments

your examples probably mean that "worried' may have two functions: predicting undesirable developments (like 'afraid') and indicating one's emotional state (like 'concerned'). The sentence stress restrictions would still apply, though.