for some people, it isn't hard to pity someone and immerse yourself in their pain but it can end up tearing you apart -> you can't destroy yourself -> he's saying let go of that person no matter how painful it may be because they're "dead" and you're being brought down with them">
the song is about attaching yourself to someone you can no longer help - enablement, perhaps. its about how you can try to save someone all you want but sometimes you just end up losing yourself in that person's problems.
"Poke the body with a stick Roll it down Ignore the moaning as it tumbles to the ground Be brave and save your day"
"To cough up sympathy isn't hard but it costs"
->for some people, it isn't hard to pity someone and immerse yourself in their pain but it can end up tearing you apart
-> you can't destroy yourself
-> he's saying let go of that person no matter how painful it may be because they're "dead" and you're being brought down with them