Hi Doesntmatter (fitting nickname xD),
Firstly, have you sought out professional help? Such acute apathy could be the result of a biological issue like a deficit in serotonin, and medication might be able to help. If you have not sought out this path I would urge you to consider it!
I will describe the philosophy I have arrived at after my own struggles with meaning and purpose. However, do keep in mind I do have a rather apathetic take on life, and do struggle with self harm and suicidal ideation on a regular basis, so TAKE ALL I SAID WITH A HEFTY AMOUNT OF SALT!
Assuming your issues stem from a purely philosophical point (a far more interesting point to argue if I may say

), I would point you to Nietzsche's arguments on the Übermensch, in
Thus Spoke Zarathustra, which I will now try to summarise and give my take on.
Our experience of reality is necessarily grounded on a fundamental nihilism, as in, there is no deeper meaning or purpose that we can fundamentally grasp given our very limited set of ways with which to perceive the world and others. That, however, means not that we should give up on a meaning, and rather that we should define our own meaning. I would even argue that that which makes us truly human is this ability to update our own directives, and set our own path using this perceived free will we believe ourselves to possess.
As such, I would argue that, based on your disillusionment with reality, you must have a core set of values with which to evaluate your life and reality, and merely find going after them pointless as it rewards you with no pleasure. However, it is also known (and the very basis of cognitive behaviour therapy if you wish to research empirical evidence on this phenomenon) that our thoughts shape and even generate our feelings. As such, I would argue that you should strive to live life as you see it to be good and righteous, not because it feels good, but because doing so
will condition you into seeing it as pleasurable; in essence, training yourself to align what you what with what you
want to want.
Hope this tirade has been of some help, and best of luck!
EDIT: I just realized I did not address your main request on "best way to kill time until I die or this passes", but I myself have found that no temporary distraction truly manages to keep the thoughts at bay (the main reason I self harm, as an extreme display of distraction-seeking behaviour I believe), and the only thing that has made it bearable has been the change in thought patterns I have described. Hope this helps!