Rainbow

I've made an attempt on poetry ,and this here is the result( I hope I didn't kill it.)

Rainbow

A moonbeam bright in darken sky,
a water well for thirsty I,
a rain that pours on dried land
is image thy on sicken mind

Where are you now, where have you been?
my lovely vision never seen.
I seek for thee, I scoured the earth,
but made are thee nay for dirt:
as rainbow high in rainy day
beyond me grasp you fled away.