I'm not sure the song was about Morrissey. It could be about an ex-lover of her instead...
what, you mean like an old lesbian?
well someone used her up and threw her away we know that. now who does that sound like? oh i wonder, i wonder.....
but, like i said, if you were in a relationship with morrissey and it ended surely that would trump all other relationships so that if you did have a susequent lover and he/she broke up with you, you wouldnt very well care enough to post videos and dejected quotes about personality-dignity-in-the-face-of-someone-elses-indifference as a response.
you would do something else. because doing such things is a sign of absolute powerlessness. of having no recourse and no currency left to get back in the game. such as i imagine is the case when morrissey shuts you out.
im not saying that they were likely hot and heavy up until then. their relationship was probably slowly dying with morrissey doing maintenance every now and again to provide the illusion that there was still something there, and when he stopped (and she realized she was old and had wasted her life on him) she couldnt handle it.
that's my guess as to the way things went. im not stating any of it as a fact but i think it's likely.