This is not unlikeable per se, but as others more familiar with the original note, there seem to be some translation problems.
In two inversions, perhaps punctuation [which often seems to be lacking where it's most needed] could help: eg
that, over a grave, will rustle its crown ...//...the dream he, in song and sadness, lost.
As already noted, 'ancient' implies a very different time frame from 'old'.

The end-rhyme here is stretching it too much:

my daily life already gone
and, like a myth large and undone.

The lines From them I know my capacity
for a second broad and timeless round. are unclear, unlike the crib's From them comes knowledge to me that I have room
for a second timelessly broad life.

The rhyme here is almost, but not quite close enough

(round whom its tender roots are thrust)
the dream he in song and sadness lost.

and that final line needs reworking to avoid the obvious inversion.

I agree with DG007 that you've got the author's "spirit", but you need to hone the rest. It's still a nice read, however.

Re-reading:

1. Rilke's IP is flawless. The translator's violation of the IP is more of a flaw here that it would be otherwise.

2. Feminine rhymes assist the tone.

3. The strange form: "Raum" is singled out in the mid section. That is the locus from which the rejuvenation comes.

Rilke is difficult, and I admire the effort to pursue the rhyme scheme. However, it fails on some basic translation principals as pointed out by others. Brave attempt, though.

Trying to figure out what I might wish to vote for and not having much luck.

Don't trust me on this, but using Swedish to seek the essence, i.e. figure out what the poem is about, I am perplexed by this translation. Isn't the original essentially a celebration of melancholia from whence creative juices flow?