Can I somehow go above 120fps?

You edit a .ini config file

The engine is locked to 120fps unfortunately

You used to be but like 6-7 months ago with one of the patch the locked it at 120 max. I have not found anyone that can break that limit. Rip

you're kidding right

They can but for me it's probably almost unnoticeable. I can barely see a difference between 60 and 120.

I felt a stab in my chest as i play on 30fps how is 120fps not good enough

The second part isn't true. The more frames per second your system renders, the more recent the latest game info you get will be, regardless of your monitor's refresh rate. Not only that, but if you play without V-Sync, your monitor can display new frames as soon as they're ready even in the middle of an ongoing draw cycle, making things even better. On top of that, higher framerates mean faster processing of inputs (both physical user inputs and networked server "inputs"), as well as outputs (networked client info you send to the server). The entire game simulation in general improves with framerate "under the hood", which we'd notice even regardless of the amount of frames actually presented to us.

You will pretty much always benefit from higher framerates, not least because having an overhead can prevent some otherwise potentially disruptive frame drops. That said, there's obviously thresholds beyond which benefits are diminishing and miniscule. Decades of competitive gaming have shown that ~100fps/100Hz is about as much as you'd ever need, there are barely competitive advantages gained from going above that. Having a stable capped framerate is also beneficial as it provides a consistent experience, as opposed to higher yet wildly fluctuating uncapped framerates. Minimum viable framerate is usually tied to a game's tickrate (rate at which the server operates), particularly because updaterate (rate at which game info is being exchanged between the server and client) is naturally dependent upon this (server and client can of course only send out info if they actually have info, which they only do if they have calculated a more recent gamestate) - you want at least enough frames to be able to send out and process the maximum amount of networked game info per second. Pretty confident DbD has a tickrate and updaterate of at most 60Hz though, so 60fps is sufficient in that respect. And if you aren't running the game in "true" fullscreen mode (which 90+% of players most likely aren't, given that this - ridiculously enough - is not an in-game menu option in DbD), you will always have V-Sync due to desktop compositing, meaning the benefits of having a framerate that exceeds your monitor's refresh rate will be diminished.

@OP: No, as has been pointed out, the devs hard-capped the game at 120fps some time ago for some reason. Although I'm reasonably sure it's just a forced variable, people that can modify the backed-in variables can most likely get rid of this cap still, but that requires potentially malicious tampering. Either way, 120fps is more than enough for DbD, if you really are noticing some choppiness, you could set your monitor's refresh rate to 120Hz (or use G-Sync if you have it).

Give Google a try. Ask it.

the game is hard locked to 120fps

I would not advise editing any config files for higher FPS, it could get you perma-banned