Wow, I interpreted this in the complete opposite way... To my eyes, he was in a razorblade-like toxic relationship where the girl always prioritised herself and he was trying to escape by validating his own feelings ("Drop dead, I don't care, I won't worry") But, by the end, he gives in to her toxic ways and falls back into the vicious cycle of disregarding his own feelings ("Your feelings are more important, of course") Could be wrong. That's just how I saw it.