What it’s like writing a poem

Sometimes it’s absolutely plain and simple .I am sitting in the garden and this enters my mind:

Random apples
Fall Silently
On unknown Newtons

That was it.

Sometimes I get a sentence,usually a line of song with music which I hum.
Quite often it is not the first line,but a middle line.I write it down when I get home:

Your words have cut my heart like  freezing snow

Then I have to decide what kind of poem.It suggests a villanelle to me so I have to get a first line

I  opened your last letter  with no clue

I like half rhymes
I  opened your last letter  with no clue
Eating  in my garden by the pond
Your sentence cut my heart like  freezing snow

I have changed the last line  as sentence implies judgement as well as a structure of words

Snow and pond  have a lot of rhyming words so I  think I can use this stanza to begin

The  Letter sent by a coward
I  opened your last letter  with no clue
Eating  in my garden by the pond
Your sentence cut my heart like  freezing snow

I opened  your last letter then I knew
I mistook your words,I had been conned
I  opened your last letter  with no clue

My heart  beat wildly wondering what to do
My eyes went blind, your hatred was unearned
Your sentence spat on me like  hail and snow

Round my mind, like birds emotions flew
No  cause nor explanation I discerned
I  opened that last letter  with no clue

My face  turned white,my voice  was muted so
Silently, I staggered from my chair
Your sentence cut my soul like  freezing snow.

What helps us when we have such pain to bear?
Will we  want to live or  love or care?
I  opened your last letter  with no clue
Your sentence,  like a  rod, beat me anew

I shall leave it like this.I might post it because if I imagine another person reads it I can see it more objectively and may see weaknesses.Sometimes I change it when I move it to a poetry website.