My interpretation - 2nd review, this one with spoilers..

Rating: 8/10 (29 January 2018)

I was surprised after reading through the reviews how apparently alot of people hated it but in their reviews, they described scene by scene what they had seen and no deeper interpretation at all.. So alot of people who hate it have just taken it "literally"? Others talked about religious interpretations.. mother nature and the history of man etc..
I mean, sure - that's what they saw and it's interesting to see, but ...
I saw it very differently.
To me the very ending revealed the interpretation that the movie is about love, relationships, life etc.
It starts with "her" delicate heart on a pedestal and "he" wants nothing but to protect it by all costs. It's the most precious thing to him.
They are happy - just the two of them, completely separate from the world. That's how relationships start.
She seeks him, calls him baby etc.. he had been away for a while.. needed the time to himself. All is not perfect.
Real world still invades that happiness:
His work makes him stressed, uneasy and restless.
Her desire is to build a home. A perfect one.
She meticulously builds every inch of it. She wants to make it perfect, while respecting his terms, as it's "his home". Likely the house "he" chose?
Or maybe since his "house burned down", he has had a difficult breakup and there's some building to be done, to get a solid foundation for a new love. She tries her best to give him everything.
His writing is struggling though, he needs inspiration.
She fears for the "house" (which likely represents the relationship or love.. she is seeing it still burnt, from maybe his past experiences). She has anxiety about it (chestpains etc.) and takes drugs/drinks/medicates herself to ease the stress. (the yellow liquid she mixes and drinks in distress)

He on the other hand escapes his stress with distractions.. He can't get motivated so he escapes it, with excuses. While she loves his books, she can't work as the muse at the time, because whenever she mentions his writing, he feels anxiety about that.. about what he hasn't managed to accomplish. She is the reminder of what feels like a burden - a pressure.
But he finds solace in a fan that reaches to him - (or maybe that one fan depicts a small bit of fans of his work that make him feel valued)

He finds alot of excuses to get his work out of his head..
He says he spends time with the fans out of respect.
Then a little later out of necessity as the fan is "dying", coughing, bleeding, not doing well (maybe depicts his fear of losing that admiration, so he hangs onto it, with excuses)
She feels it intruding on their life. The outside world constantly tries to get into their business.. their sexlife, their private life, their intimiate life details. (the questions and intruding behavior)
She'd just want him. Only him.
So again, she medicates herself, keeps building the house - and flushes her heart down the toilet while cleaning the mess of the "fans" (she pushes her emotions to the side, hides her disapproval, as she's in so much love for him).
She obliges his desires...
But he puts his fans and need for validation from other people ahead of her. Constantly. This eventually breaks her heart. (it shatters on the ground thanks to these fans who intrude too much)... That's when he sees his errors. It troubles him severely. It leads to a ton of conflict.. He shuts his heart off entirely - the most precious "room" of their love.
For a while he is upset.. doesn't want to see the fans, who are still in their life.
But he's not with her either.. he has withdrawn from everything for a while...
Things get increasingly restless with people intruding on their lives and he has to address the outside world again... Things get so disastrous it leaves a permanent mark on their life. A disaster that can't be washed clean, can't be hidden under a rug.. they try to bury this horrible event out of sight, into the basement, into a safe, into the wall, but it just keeps busting out and keeps on reminding of itself with small signs constantly.
When he still spends time with the man and his family after their tragedy, it's likely a metafore of how something happened and he "needs to be there" for them and he accepts it as another excuse...
"I have to support him he lost a son, and he's dying"... but that side quickly turns into parties. It's not funeral service, it's celebration... it spreads and spreads, with her husband spending more and more time drinking with the fans or partying with the outside world while she feels more or less powerless and can't even make him hear her voice.
Totally losing control over the situation... but she obliges, tries to be polite, tries to be accomodating - and medicates/drinks out of necessity...
Her anxiety about the house she is building (they are building for themselves) is constantly in her mind, as she keeps worrying that the outside world destroys it. And it damages it in many ways.
She finally stands up for herself, reaches her breaking point... it wakes him up.
The passion sparks through all their troubles.. she gets pregnant.
She no longer feels like a burden that he escapes: Their love is there again.. she pours her medication down the toilet and stops it (drinking or drugs?).. he makes an effort to change... he finds motivation out of all of their tragedy and their love. He finally writes, with her as his muse.
For a while, it all seems perfect again. It's the two of them again.. he is successful in his work... but ... upon reading his work, will that success make her lose him? There will be even more fans? What if it consumes him?
He promises she will never lose him.... But before she knows it, the publications already know of the book.. she was never asked.. then come the fans - the publicists - the outside world. She can barely get a moment of his time anymore. She doesn't know the people in their lives, she can't focus on building the house.. she feels the love dying. (The houses "heart" she listens to represents their life, their love. The house is the foundation of the relationship.)
All spirals into total chaos. He parties, he invites people over, she feels like a famous man's trophy on the sidelines.. she doesn't want in the spotlight at all... But she feels tremendous amounts of pressure and that there is zero privacy in their life anymore, with every nook of their house filled with people - most of who don't even know who she is....
People around him seem to only care about exploiting his fame or wanting to scavenge things out of them. But he is addicted to the validation. Eventually, the excuses stop and he admits it:
I don't want them to go! He doesn't want to stop.
Maybe he still drinks?
Maybe he still does drugs with them while she quit because of the pregnancy?
(After all, as soon as the first stranger arrived, they had "upgraded" from tea to alcohol.)
She wants out of all of it.. to focus on the child.
It's too much, but she can't get away.. she is trapped in the life with her loved one, who won't let the publicity go.
The stress of that life keeps on bombarding her with stress as she keeps on trying to escape.. but it just keeps getting worse and worse, with even people who say they'll help or familiar faces that first seemed friendly, turning out to be horrible sources of stress... It all escalates to total chaos, so she withdraws from it... he follows her eventually, gives her a hand and promises to stick by her.
But when she wants to head to the door (leave it ALL behind) he pulls her to stay in the situation.. Again, she wants to go one way, he insists on another, until they seclude into hiding.
The outside noise settles down for a while. She gives birth... maybe it's meant to portray that it was too early, as it came in the middle of such stress?
They stay in seclusion watching over the weak baby... She doesn't trust him. He refuses to let the spotlight completely go while she asks for it several times...
He then betrays her trust when she lets her guard down.
He goes to the spotlight... the child dies.
She blames it all on the outside world.. she can't hold her anger in. She snaps at the world, at him, she has lost her child and she shows her aggression to the outside world in full force. She gets absolutely attacked for it...
The wife of the icon the masses love is seen in public like that and they attack her, berate her, hate her... she gets abused by it all.
She never asked for it.
So she has had enough.
The "heard" of the house dead, the foundations completely break under her and she decides to end it all.
He begs for her not to. But it's too late. She burns it all down.
Deep down, her love still remains.. or "a" love still remains.
He starts again.. from the ashes.
Another relationship starts.