Now I believe in good and bad days

Last week I played so well, increased my blitz by +250 rating breaking my record too. I didn't even have to calculate, tactics I just saw them without thinking, I felt like my games are easy and my victories clean.

Today it's the exact opposite. My brain is literally malfunctioning and the mistakes I make are just unbelievable. I am leaving my pieces hanging all over the place, pawns... One game I lost by putting queen right in front my opponents rook just like that, free to take and after almost a minute of thinking too. I literally can't focus, every move I make I have no idea what I am doing.

It's crazy I feel like my brain died

C´est la vie

aneb po posvícení bývá s...

I am not stressed and definitely not tilting. My play has nothing to do with my mood or mental state, my brain simply refuses to cooperate. I can't focus.
I am thinking now, last week I've been eating a lot of good, healthy food, but today I only had a fast food. I really wonder now if trash food can drop my performance like this and I am not even kidding

your brain needs brakes. Its normal... stay away 1 week from chess. your brain is burnout

I guess brain is like a muscle it gets tired, needs rest and must also get fuel. When you next feel like that stop playing chess take a break.

Also try to remember what got you in the peak playing state before and try to recreate that next time (after your break) cos that sounds really positive!

This dramatic swing is a classic chess experience; you're feeling the crash after a period of intense focus, and mental fatigue is causing the uncharacteristic blunders. The only real solution is to step away from the board for a day or two, as trying to force yourself to play through this kind of slump will only lead to more frustration and losses.