I turned my Xbox series to 120Hz now my screen is showing anything up and I can’t see it...

it means your tv does not support more than 60hz.

1. Power off your console, and then unplug the mains lead to ensure that the console is completely powered off.
   
2. Wait 30 seconds, and then plug the mains lead back in.
   
3. Press and hold the Pair button and the Eject button on the console, and then press the Xbox button  on the console.
   
   Note The Xbox Series S and the Xbox One S All-Digital Edition do not have Eject buttons. You can bring up the Xbox Startup Troubleshooter on this console by holding only the Pair button (steps 3 & 4) and then pressing the Xbox button .
   
4. Continue holding the Pair and Eject buttons for 10-15 seconds.
   
5. Listen for two “power-up” tones a couple of seconds apart. You can release the Pair and Eject buttons after the second power-up tone.
   
6. The console should power up and take you directly to the Xbox Start-up Troubleshooter.
   

Xbox doesn’t need an update; i am on Home Screen; I can’t really load or do anything though; any actions freeze and take minutes to load games and apps or an app; can’t open anything in settings as “it takes too long to start” the xbox is horrendously slow even though i just factory reset it, and updated mind you, but everytime i turn it off i get a black screen turning it on and have to power cycle, sometimes it gets stuck on green screen but luckily for now after a few attempts i can still be brought to home screen, i just honestly can’t turn the xbox off because i don’t know if it will end up breaking again and have to factory reset it but i can’t even use the xbox as is, as everything freezes and takes forever to start or do anything, had a game download to 75% just for it to stop for some reason and i can’t pause the download or anything because it freezes and takes too long; debating opening the xbox and cleaning though it’s been cleaned before and it still eventually ends up useless; TLDR: xbox can’t be turned off or gets stuck on startup, several tries eventually show home screen but xbox is too slow to even use or do anything with

you need a monitor that shows exactly 120hz in the edid information, if it shows 119.86 which a lot of monitors do then it will not work, there are monitors out that are designed to work with consoles now that have the exact standards.

pc can pretty much use anything, consoles can't.

My monitor supports 60, 75, 85, 90, 120, 144, 165, used this on my series s and 120hz works fine as 120 is exactly 120hz.

Yes I have 4K too. But right now, with my 1440p 120hz settings on. If I start OW2, my screen goes black then “hdr on” pops up. So am I no longer gonna run 120hz?

Still down, I can’t even sign into live.. I can get to my Xbox home screen But can’t sign in or click onto anything.. hopefully it’s up soon