I knew surburban civil servant

[poppoetry]

I can see what you mean about the structure having problems. I think that the root of some of the problems is your struggle to find rhyming words, thus creating lines that really serve no purpose. From the looks of things, you've been attempting to use lines with nine syllables but often have lines that are too short or long due to excess information. For example:

Paul sits in the far corner every day. - Cutting this line down to nine syllables rather than ten matches the line below.
His neat desk there, all tidy'd away. - I believe the word you're looking for is 'tidied'.
Coat stand waits, naked there. - This whole line needs some revising. Try to add something to this so it fits the rhythm.
Paul catches the 7.40 from Surbiton, he's on his way. - As with the above, this line just doesn't fit. It's much too long, and provides information the reader doesn't need.

I'm not going to go through the rest of the poem because I'm already looking too in-depth at it. However, I wonder if the poem would be more effective without any mention of Surbiton (or for that matter any locations)? I know the poem is personal to you, but 'Surbiton' doesn't rhyme well and seems to be a source of a fair few structural issues. Besides, I'm British and I had to look Surbiton up to find out it existed. If you chose not to mention any place names in the poem, you may find yourself being less restricted - and the reader will be able to connect more with the poem and its message.
One more nitpick: The use of both 'mum' and 'mom'. The poem is set in England, so naturally I'd go for 'mum' but please don't use both.

Thanks for the suggestion, you're 100% correct, I never thought of taking out Surbiton but now it seems obvious, structure is problematic ok and I'll take in your suggestions and revise, I'll try and restrict the amount of syllables I use and stick to it, I now see how to develop a poem and thanks.