In 1887 at a Philadelphia sanatorium, Dr. Weir Mitchell, who is alluded to in "The Yellow Wallpaper," treated Charlotte Perkins for a "nervous condition." The treatment was not only unsuccessful, but harmful. Perkins herself stated that she wrote her story, in part, to expose the harm that this doctor dealt sensitive, artistic women who were restricted from an creative or higher-level activities during their treatments.
In the setting of this story, the Victorian Age, women's primary purpose was to be wives and mothers. Any other activities in which they engaged were considered trivial amusements; no credibility was given to an illness such as "postpartum depression." Since the narrator's husband, John, who is a physician only believes that physical things are real, when he cannot find any physical symptoms for his wife's illness, he feels that she is a hypochondriac and, so, he exerts his control over her as a means of asserting himself and, perhaps, teaching her a lesson for feigning illness. And, as support for his ideas, he has Dr. Mitchell.
As a consequence of this repressive situation brought about by a chauvinistic society, the narrator feels that her wishes have been ignored. When her desire to have a room that has "a lovely view of the bay and a little private wharf...with a shaded lane that runs down from the house" is rebuffed and she is cruelly forced to "rest" in a room that tortures her psychologically. For, she is repulsed by the ugly yellow of the wallpaper and its design which disturbs her artistic side.
This paper looks to me as if it knew what a vicious influence it had! there is a recurrent spot where the pattern lolls like a broken neck and two bulbous eyes stare at you upside down. I get positively angry with the impertinence of it and the everlastingness. Up and down and sideways they crawl, and those absurd unblinking eyes are everywhere....The furniture in this room is no worse than inharmonious...
That she would be disturbed by this wallpaper her husband should have known since he is aware of her artisitic spirit. It seems part of his cruelty that he ignores this aspect of his wife. As a result of her confinement with no view from the window and nothing to do but stare at the hideous wallpaper, the narrator becomes obsessed with the pattern, following it "by the hour." She determines "for the thousandth time that I will follow that pointless pattern to some sort of conclusion." Because, as she states, she knows "a little of the principle of desirn, and I know this thing was not arranged on any law of radiation, or alternation, or repetition, or symmetry, of anthing else," the narrator is artistically disturbed by the paper's pattern. She describes it further as "'debased Romanesque' with delirium tremens...waddling upa dn down in isolated columns of fatuity." Soon, the "effort is getting to be greater than the relief," and she loses her mental grip.
Still, her husband ignores her illness, speaking in a patronizing tone:
Bless her little heart!...She shall be as sick as she pleases! But now let's improve the shining hours by going to sleep, and talk about it in the morning!
Without any psychological help, the narrator slips further into her obsessive occupation. She imagines that there is a room trapped behind this paper, a woman who symbolizes herself. Subconsciously resolved to escape her confinement so that she can get well, the narrator projects her feelings onto the "woman" whom she must help escape the paper.
Stream-of-consciousness writing is where the narrator of the story reveals all of their thoughts, no matter if they are connected, smooth, or logical in their progression. Let's say that you are just sitting there, thinking, daydreaming, and if you were to expose each and every thought that pops into your head, it would probably be pretty all over the place. Our brains are each unique, and what we think and in what order, reveals aspects about our true personality. In fact, Freud, who is famous in psychology, believed that stream-of-consciosness revealed our real selves, along with any subconscious and conscious issues and problems that we had. If we don't filter our thoughts, then one can truly see what we are thinking and feeling.
Applied to "The Yellow Wallpaper," her stream-of-consciousness style reveals her struggle with accepted female roles of the time, and her deteriorating mental state. During the time period that the story was written, women's entire purpose in life was to prepare for marriage, and to be happy in marriage and in bearing children. She was to be subservient to her husband's wishes. Her thoughts show her fighting against herself to fit this role. For example, consider the following passages:
"John laughs at me, of course, but one expects that in marriage...I get unreasonably angry with John sometimes. I'm sure I never used to be so sensitive. I think it is due to this nervous condition.But John says if I feel so, I shall neglect proper self-control; so I take pains to control myself -- before him, at least, and that makes me very tired."
Her stream-of-consciousness style reveals to us that she is struggling with conforming to the "perfect, quiet wife" role that is put before her, and having a hard time. She doesn't admit this openly, but as she puts down all her thoughts, unfiltered, it is revealed.
Her deteriorating psychology is also revealed through the writing style. We see her thoughts get more and more fixated on the wallpaper; she stops talking about other things, and talks mostly about it. Her thoughts show her increasing paranoia of Jenny and John, even though outwardly she doesn't show that anger. So, the writing style helps reveal to us just how sick she really is. I hope that those thoughts help; good luck!