Since you have already accepted an answer, I tried to put my musings on the matter in a comment, but they did not fit--surprize, surprize... Well, anyway:
What is happening in your story and what any of your characters thinks is happening in their reality are not necessarily the same thing. Quite the opposite--the concept is called "unreliable narration" and it is a great tool when used properly.
In short--it is perfectly normal for a character to be disoriented to some degree; it is not going to stop your readers to understand what is going on because you let them see the bigger picture than the characters see due to the limitation of the time-space continuum they inhabit--no one is able to be at several places and at the same time at once, no one, but you, the author, and it is your choice to take your reader with you or let them wonder a bit.
It is hard to evaluate the effect of one scene without reading the whole manuscript, but what I immediately imagine (alliteration not intended) when I hear "first-person" and "suddenly awoken from a nightmare" is a short and emotionally charged piece, perhaps written in present tense to relate the immediacy of what is happening, describing scattered fragments of what is thrown at her and her desperate attempt to separate the nightmare from reality, and so on...
And guess what:
Even in that torrent of seemingly unfiltered and random things, she is suddenly exposed to, which require her immediate reaction, you, as the master of her Universe, can easily embed bits and pieces meant to be spotted by the readers and lead them along your story even if the delivery mechanism of this particular scene is deliberately out of tune.
It can be anything--since I did not read your story, I will just throw in some random poorly thought-through examples (SELFLESSLY AVOIDING PLUGGING IN A PIECE OF MY OWN GENIOUS WRITING):
The attackers might wear black or what seems to be black in the poorly
lit setting, but when the fight is over there is a torn piece of red
fabric left behind, which mean that they belong to a totally different
faction, of which she is unaware, but the readers already know.
The speak different language, the one she doesn't recognize and keep
repeating some word which sounds like "@#$%^&", which means nothing to
her, but your readers just learned what "&^%$#@" (correct version of
the word) means, and it indicates great immediate danger to your
protagonist, who might escape this for now without realizing it, but
your readers will know better and worry and feel sympathetic to her.
And so on. I hope I am making my point clear: you are free to use a disoriented character to the extent where it becomes annoying (you be the judge where to stop), just do not forget to advance the whole story forward.
Best of luck!