Hi Paul,
Interesting lyrical ideas, which I think work really well. The pattern of the lyrics is the same throughout the song, and actually lends itself to your melodies that you've come up with. I wouldn't worry about that, if you've ever listened to Dire Straights, he gets away with simple melodies and beautiful lyrics.
However you find yourself writing a song is the right way for you. Enjoy the process, and learn from it, we can always improve.
Perhaps a simple way to bring some more interest to the chorus might be to add a longer counter-melody, perhaps with a female vocal. Maybe ooh or ahh sounds, or other linger syllables that would make the song feel more complete.
Other than that, keep it as I, I enjoyed it...