I am pretty much disgusted with human behaviour most of the time.

Sylvia Plath 
Letter to Edward Cohen
11 Aug 1950

I know I’ll always think of you with something like hurt and nostalgia—and a great deal of love.

Sylvia Plath
Letter to Ann Davidow
16th March 1951

I do think that it is hard for me to share myself with everyone. My introspection and queer thoughts always make me feel no one will understand—except someone I love, like you. When I love someone, I make myself increasingly vulnerable to them—and give them the power to hurt me by letting them know my sensitive spots.

Sylvia Plath 
Letter to Ann Davidow
20 May 1951

After Class Day, it was a two hour tea at the headmaster’s house, and I got so damn sick of making small talk with mothers of boys and fiancées and young wives that I thought my sweet girlish smile had frozen to my face. I felt like drowning myself in the iced tea bowl, in a flurry of mint leaves.

Sylvia Plath 
Letter to Marcia B. Stern
12 Jun 1951

If I lived by the sea I would never be really sad. I get an immense sense of eternity and peace from the ocean. I can lose myself in staring at it hour after hour.

Sylvia Plath 
Letter to her mother, Aurelia Plath
18 Jul 1951

My bookcases are overflowing—shelves of novels, poetry, plays, with clots of philosophy, sociology & psych. I am a bibliomaniac (with a slight touch of nympho thrown in!)

Sylvia Plath 
Letter to Philip E. McCurdy
14 Apr 1954

Oh, I love you more than the alphabet and Roget’s thesaurus combined.

Sylvia Plath 
Letter to Gordon Lameyer
29 Jun 1954

I get so tempted to take you verbally by the scruff of the neck and shake you when I hear you talk about solitude, or exile, or what verges on the horrible “Ennui” (which is more than boredom of the dilettante, but rather a huge and horrible cosmic yawn of the intellectual, highly sensitized being in face of life and death and whatever you may mean by eternity) because the cataclysmic downward gyre I plummeted to symbolic death in last summer, when the center did not hold because there was none, or rather (as you wrote), too many, has given me an understanding of the black and sustained hells a mind can go through . . . and the enormous insulated loneliness when you feel that no human hand or love could reach or move you (if even one could it would be allright, because that one would symbolize contact with the human race).

Sylvia Plath 
Letter to Melvin Woody
5 Jul 1954

Now with me, writing is the first delight in life. I want time and money to write, both very necessary. I will not sacrifice my time to learn shorthand because I do not want any of the jobs which shorthand would open up, although those jobs are no doubt very interesting for girls who want them. I do not want the rigid hours of a magazine or publishing job. I do not want to type other people’s letters and read their manuscripts. I want to type my own and write my own. So secretarial training is out for me. That I know.

Sylvia Plath 
Letter to her mother, Aurelia Plath
10 Feb 1955

I keep reading about this damn Adrienne Cecile Rich, only two years older than I, who is a Yale Younger Poet and regularly in all the top mags; and about 23-year old blondes from Radcliffe who are already selling stories plus climbing alps. Occasionally, I retch quietly in the wastebasket.

Sylvia Plath 
Letter to Gordon Lameyer
28 Jul 1955

I have no illusions about my writing any more; I think I can be competent and publish occasionally if I work. But I am dependent on the process of writing, not on the acceptance; and if I have a dry spell, the way I did last term, I wait and live harder, eyes, ears, and heart open, and when the productive time comes, it is that much richer.

Sylvia Plath 
Letter to her mother, Aurelia Plath
25 Jan 1956

So many Englishmen think women become unfeminine when they have ideas and opinions.

Sylvia Plath 
Letter to her mother, Aurelia Plath
28 Mar 1956

I feel completely paralysed, away from you; I’m not hungry; I can’t sleep; can’t read; can’t think. I’ll be all right, but not by recovering from missing you; only by learning, and it must take a good deal of learning, how to live with this huge whistling hole in my guts and heart.

Sylvia Plath 
Letter to Ted Hughes
4 Oct 1956 

The British arrogance—that old smug commercial colonialism—alive still among the Tories, seems inexcusable to me.

Sylvia Plath 
Letter to her mother, Aurelia Plath
1 Nov 1956

We began mooing at a pasture of cows, and they all looked up, and, as if hypnotized, began to follow us in a crowd of about twenty across the pasture to a wooden stile, staring, fascinated. I stood on the stile and, in a resonant voice, recited all I knew of Chaucer’s Canterbury Tales for about twenty minutes. I never had such an intelligent, fascinated audience. You should have seen their expressions as they came flocking up around me. I’m sure they loved it!

Sylvia Plath 
Letter to her mother, Aurelia Plath
8 Apr 1957 

I have thought of you so frequently this past year that I imagine, I guess, that by some mystical intuition you may well be aware of this.

Sylvia Plath 
Letter to Dorothea Krook
25 Sep 1958

I have become a verb, instead of an adjective. It is as if this divorce were the key to free all my repressed energy, which is fierce from six years of boiling in a vacuum.

Sylvia Plath 
Letter to Dr. Ruth Beuscher
21 Oct 1962

I shall forge my writing out of these difficult experiences—to have known the bottom, whether mental or emotional, is a great trial, but also a great gift.

Sylvia Plath 
Letter to Olive Prouty
25 Oct 1962

This year will be the hardest financially in my life (I hope), as I have to make bold and considered investments, as in this flat, in order to enable me to work toward a future. Ted’s sticking me here, helpless & with all these difficulties & blithely walking out, I shall never forget or forgive. I despise him. I think he is a coward & a bastard & want him to have nothing to do with me or the children. He is a gigolo now, vain & despicable.

Sylvia Plath 
Letter to her mother, Aurelia Plath
22 Nov 1962

I feel a simple act of will would make the world steady & solidify. No-one can save me but myself, but I need help & my doctor is referring me to a woman psychiatrist. Living on my wits, my writing—even partially, is very hard at this time, it is so subjective & dependent on objectivity. I am, for the first time since my marriage, relating to people without Ted, but my own lack of center, of mature identity, is a great torment. I am aware of a cowardice in myself, a wanting to give up. If I could study, read, enjoy people on my own Ted’s leaving would be hard, but manageable. But there is this damned, self-induced freeze. I am suddenly in agony, desperate, thinking Yes, let him take over the house, the children, let me just die & be done with it. How can I get out of this ghastly defeatist cycle & grow up. I am only too aware that love and a husband are impossibles to me at this time, I am incapable of being myself & loving myself.

Sylvia Plath 
Letter to Dr. Ruth Beuscher
 4 Feb 1963

Sylvia Plath died on 11th February 1963, aged just 30. The above snippets are from two collections of her letters: Letters of Sylvia Plath Volume I: 1940–1956, and Letters of Sylvia Plath Volume II: 1956–1963.