I Have What Appears To Be An Epidermal Cyst, Which

I have what appears to be an epidermal cyst, which I've had for some time. I, of course, have squeezed. It produced a foul-smelling, creamy-white substance, & I thought that would be the end of it. However, I couldn't seem to leave it alone & have not angered it (redness, swelling, soreness). How can I treat this at home?