It now seems to be coming out of the manhole in the laundry. Once I finish my washing, I'm gonna evacuate the room and try to tape the door shut or something (it doesn't stay closed and I can't seem to fix it)
I feel like I'm trying to cordon off a bloody disease in Disneyland at this point
That does sound like something's died in the roof cavity. I'd postpone investigating until daylight - and preferably get a professional to deal with it. So many different rooms affected.