John Keats was only 26 years old when he died, however, he was considered, along with Wordsworth, to be the Romantic poet of the 19th century.
He was 14 when his mother died of tuberculosis, and 15 
his guardian apprenticed him to an apothecary surgeon.
John left the medical field soon after
to devote himself to poetry.

John Keats was not well, and moved to Italy in hopes the air
there would make him well.  It was not to be.
He died of tuberculosis
at age 26.

Before his death John Keats suffered depression and melancholy.

His poem "When I have fears that I Might Cease to Be"
expresses his feelings.

When I have fears that I may cease to

         be

  Before my pen has glean'd my teeming 

         brain,

Before high piled books, in charactry, 

  Hold like rich garners the full-ripen'd 

         grain; 

When I behold, upon the night's starr'd 

         face,

  Huge cloudy symbols of a high romance,

And think that I may never live to trace

  Their shadows, with the magic hand of 

         chance;

And when I feel, fair creature of an hour!

  That I shall never look upon thee more,

Never have relish in the faery power

  Of unrelenting love:--then on the shore

Of the wide world I stand alone, and think

Till Love and Fame to nothingness do sink.

O soft embalmer of the still midnight,

   Shutting, with careful fingers and benign,

Our gloom-pleased eyes, embower'd from

     the light,

   Enshaded in forgetfulness divine:

O soothest Sleep!  if so it please thee,

     close,

   In midst of this thine hymn, my willing eyes,

Or wait the amen, ere thy poppy throws

   Around my bed its dewy charities;

   Then save me, or the passed day will

     shine

Upon my pillow, breeding many woes;

   Save me from curious conscience, that 

     still lords

Its strength for darkness, burrowing like a 

     mole;

   Turn the key deftly in the oiled wards,

And seal the hushed casket of my soul.
 
 

Bright star, would I were steadfast as

      thou art!

  Not in lone splendour hung aloft the

      night,

And watching, with eternal lids apart,

   Like Nature's patient sleepless Eremite,

The moving waters at their priestlike task

   Of pure ablution round earth's human 

      shores

Or gazing on the new soft fallen mask

   Of snow upon the mountains and the

      moors:

No -- yet still steadfast, still unchangeable,

   Pillow'd upon my fair love's ripening

      breast,

To feel for ever its soft fall and swell,

   Awake for ever in a sweet unrest,

Still, still to hear her tender-taken breath,

And so live ever -- or else swoon to death.