Is DLv. 19 really that much harder than DLv. 18 and other previous levels or is Konami just playing with me

I've climbed every previous DLv. with relatively minor setbacks I would say. Today, after going on an 8 duel long win streak, I finally reached DLv. 19, where I lost 6 duels in a row and immediately got put back into DLv. 18. I don't think that I am a third-rate duelist, nor that I have a fourth-rate deck, because then I wouldn't have been able to get to this point.

So is DLv. 19 really that much harder than every other KC Cup level? Did anything similar happen to y'all too?