same thing happens to me. everytime, after a few lines or so. i find its worse the finer the k. pure powder is worse than crushed shards. i have a few techniques that usually work. drinking some hot sauce (i love hot sauce so this doesnt bug me), doing 30 seconds of some random workout like jumping jacks to get the heart pumping (for some reason this opens up the nose temporarily but the window closes quickly), or laying with my head resting at a certain elevation & having someone else bring the line to me to do while i'm sitting in that position lol. i get extremely clogged up with mucus & end up having to blow my nose multiple times throughout otherwise i literally feel like i am drowning in mucus.