At first, I thought he was talking about someone who has ruined his life as well as their own. But now I think he is talking to himself. He messed up badly. The army/that you mowed to the ground" is all of the people around him that he hurt in the process. He was selfish, and only ever gave a damn about his own opinion. If he cuts all of the people who care about him out of his life, it won't matter if he messes up again because he'll only be hurting himself. Instead of trying to make amends, he's given up and decided he'll "be staying down/where no one else gonna give [him] grief." His "staying down" kind of sounds like suicide, if you ask me.
At first, I thought he was talking about someone who has ruined his life as well as their own. But now I think he is talking to himself. He messed up badly. The army/that you mowed to the ground" is all of the people around him that he hurt in the process. He was selfish, and only ever gave a damn about his own opinion. If he cuts all of the people who care about him out of his life, it won't matter if he messes up again because he'll only be hurting himself. Instead of trying to make amends, he's given up and decided he'll "be staying down/where no one else gonna give [him] grief." His "staying down" kind of sounds like suicide, if you ask me.