Dream on...

Sleep...

Sleep well...

Don't worry!
I'll stay be here when you wake up!

Sleep...

Sleep and dream on!

Dream you're flying
in a the highest sky
Or you're swimming on in the blue sea

Sleep...

Don't worry!
To At/by your side I'll always be
For better or worse
And when you need of me. (or "And when you have need of me")

Sleep and dream on...

Dream the most beautiful of dreams
And believe that a one day it will happen.

And what about me?

Don't worry.
I'm okay!

Okay because my dream happened
And the person that, in my dreams, always visited me
Today is in my arms
Forevermore

This is very nice :) Usually we wouldn't say "highest sky," but in a poem it makes sense.