Cian,
You asked for brutally honest,,, I think it is terrific.
Here are some suggestions as requested:).. You could bring in some more drums/beats/rhythm on the 2nd verse around 1:03 heading into the chorus. Bring it up a bit before hitting the Chorus.
1:19 to 1:35 is a really awesome, Very strong Chorus. You could repeat it again rather than that bridge section from 1:36 to 1:58. I think if you had to pick a weak section it would be 1:37-1:58. Didn't really get it...... I was expecting verse 3 to come in at 1:37, or a repeat of the chorus. After you say "pushin pills for this heartache", it would be cool to add silence and then head into the next verse.
I think you could also add some vocal counter-point during the chorus....
I would kill the train beat during the Chorus at 2:16 and repeat the beat between 1:19 to 1:35 at this point. The Chorus is super strong, I wouldn't confuse the listener by changing it up too much.
Hope this is helpful. The song is really terrific as mentioned, these are minor production nits and more personal taste than anything. Great work.
Regards