well my interpretation would be that person a in the relationship gets scared that they're going to be left in the dust, so, as a coping mechanism or a last effort?, tries to make person b feel bad in hopes that they'll realize what they've done and stay with person a. i mean that's what i'd gather from the beginning lines - in fear, doubtful, then the rest of the song feels enraged. or another would be that they're sick of getting mistreated by person b and they're just so fed up with them they express it. but im pr sure it's easy to interpret this song sooo