Just crossed 1PB total upload, felt like bragging a bit. I'm sure others who have been at this for years and years would put my numbers to shame, but I was excited to see that 4th digit tick over! :)
so you actually have no idea whether "your ISP throttles your shit crazy". it probably does not, because if you are using vpn, that would affect all your other traffic as well.
try to stop using the vpn and test the behaviour of the torrent again.