It could be a combination of things. It sounds like it was some pretty good stuff and possibly a different strain than you were used to. I suspect it might of been laced with pcp.(Hope I don't get banned for this,I'm just trying to help). I've had experiences like that in the old days when pcp laced pot was a lot more common. Its also possible that it wasn't properly flushed during the last 2 weeks of its life so you ended up smoking some nutes.