I really sympathise with you OP...
I’ve no idea what is going on in the mind of your friend... but it’s mind boggling to read some of the responses you’re getting, suggesting your friend can do whatever she wants because it’s her apartment.
We can all choose to behave inconsiderately, if we want to. Doesn’t make it right.
To say that the gift giver (friend who offered a free and exclusive stay at her apartment, in order for you to write uninterrupted) is entitled to do whatever she wants (I.e. stay there and make it impossible for you to write as planned) ‘because it is her apartment’ and therefore is entitled to do whatever she wants regardless of the impact it has on those around her... is completely missing the point.
It was offered as a gift.
That would be like saying, “I am offering you the gift of a free meal because I know you’re hungry right now.”
But when the meal arrives at the table the ‘gift giver’ nestles up to their hungry friend and says, “don’t mind me tucking in, do you?”
Then proceeds to rearrange the food on the plate and starts sloshing unwanted condiments on every forkful the hungry friend is trying to eat, making it stressful, if not impossible for them to eat the meal.
And all the while, the hungry friend says “I’m sorry, I’m quite hungry and I was under the impression that you had gifted me this meal because you knew I was hungry? I’d really like to eat it please...”
And a particular bunch of people stand around wagging their fingers, saying:
“You didn’t pay for the meal, so shut up and be grateful. Your friend can do whatever they like... if you wanted a meal you should have bought it yourself.”
This attitude not only entirely misses the fact that life is not an emotionless bank transaction (and is actually full of complex and colourful dynamics) ... but is also incredibly patronising towards the gift giving friend... as it’s assuming they haven’t the faintest idea what a gift really is.
Good luck with your writing OP, I really hope you can salvage things.
I work in the NHS and I’m expected to write complex therapy reports, summarising years of in-depth therapy in an incredibly noisy and chaotic office. Today was especially loud as we had 5 maintenance guys in replacing a smashed window, shouting and swearing and jumping off the desks...
Whilst I really like my colleagues, I have to listen to white noise, directly through my headphones, as loud as it will go... in order to get any reports done.
I used this today and (if it’s the kind of thing that works for you), I can highly recommend: