I've recently been through this, I went from 1549 in blitz and crashed to 1388 in one sitting, that's a loss of 161pts, it was because I was playing too much.
I've clawed it back by winning 30 of my last 42 blitz games after a break, moral of the story, when you're on a losing run or tilted, stop for a while, that can mean a few hours rather than days as in my case, makes a massive difference.
Yeah, I'm def in a chess slump right now whether its a massive curbstomp or 1 bad move that changes everything. I think I have issues seeing checkmates on my own end