when i had staph in jail, the officers said that once it pops it's more at risk for infection, so they considered it an emergency.
My advice is keep it clean and take the antibiotics, keep an eye on it, if it feels better good, I think you'll be fine man.
If you must shoot up, do it in a different area for a while, though like i said, i think the best way you could use it is plugging.
Is this fet powder that your getting or some sort of pharmaceutical?
Also, don't squeeze the pus out, just let it come out naturally