Now I don't exactly agree with the other interpretations but to each his own I suppose.
"A low feeling
No healing
A heart of stone"
To me, he suffers from depression. Although I know "plunder" means to steal/ravage/pillage as the above comments suggest, in this context I think it means he's become devastated or ruined as a result of depression and needs help.
"And as I plunder
As I fall astray
And if I should wonder
Could you help me find my way"
Now I don't exactly agree with the other interpretations but to each his own I suppose.
"A low feeling No healing A heart of stone"
To me, he suffers from depression. Although I know "plunder" means to steal/ravage/pillage as the above comments suggest, in this context I think it means he's become devastated or ruined as a result of depression and needs help.
"And as I plunder As I fall astray And if I should wonder Could you help me find my way"
Yet no one helps him. He feels alone.
"No passage Here after You're on your own"
I may be wrong but you get the idea...