I am looking for the poem that starts with these lines:

  "I loved, and then I loved no more
   Let joys and grief perish and leave dismay to ring the knell
   of youth.
   He stood beside me, the embodied vision of the brightest dream
   Who like the dawn heralds the day of light."

Hello.

The poem is part of a work called "Fragments of an Unfinished Drama."

The poet is Percy Bysshe Shelley.

 LADY:
Oh! would that I could claim exemption
From all the bitterness of that sweet name.
I loved, I love, and when I love no more
Let joys and grief perish, and leave despair _50
To ring the knell of youth. He stood beside me,
The embodied vision of the brightest dream,
Which like a dawn heralds the day of life;
The shadow of his presence made my world
A Paradise. All familiar things he touched, _55
All common words he spoke, became to me
Like forms and sounds of a diviner world.
He was as is the sun in his fierce youth,
As terrible and lovely as a tempest;
He came, and went, and left me what I am. _60 

source:
"Fragments of an Unfinished Drama."
The Complete Poetical Works of Percy Bysshe Shelley, Volume I, hosted
by blackmask.com
http://www.blackmask.com/books100c/shlyone.htm#1_8_3

----------

search terms:
"embodied vision of the"
"the sun in his fierce youth", shelley 
"Fragments of an Unfinished Drama."

I hope this helps.

I am astounded at how quickly my question was answered.  I have been
searching for the poem for years and am delighted to have finally
found it thanks to your wonderful researcher.

Thank you for the tip and the kind words.
-juggler