I think the song is about rehab.
First verse is reflecting on the road ahead, his struggles, and the last overdose that led to him being admitted.
Turning down the lights refers to the lights in a rehab clinic at night.
The chorus is about having..well the whole world in front of him, and his struggle to clean up and take advantage of that (armor breaks, please don't give up). Eyes being wide awake referring to him seeing his addictions for what they are now that he's free from their influence.
Second verse is his inner demons talking to him. The voice that puts the pain in reverse being someone that's a positive and encouraging force in his life (his wife? kids?)
Bridge is about him fighting back from relapses.
Now it's possible that I just had too much time on my hands and I read too far into this song... but I just wrote these possibilities as I listened to the song in real time. It's how I chose to make sense of the lyrics.