What kind of fake ketamine was this

I know my ketamine well, and instantly if it's fake or not.

I remember feeling the exact same feeling once before at a club trying someone else's, and it recently happened again, from k that someone gave me.

I took one line, and there was no warmth or love or psychedelic goodness or love. Just a horrible empty feeling like I'm falling, the most distinctive part is seeing my vision kind of double, like as I feel I'm falling there's no hallucination or trippy visuals, just a boring kind of halo double vision almost like a light ripple but with normal vision. I feel small and like I can only talk quietly and don't want to move at all, it's a negative empty feeling that I want to wake up from.

People take this shit thinking it's ketamine? It's so obvious that it's something nasty.

What could it be?