Microphone is picking up output audio like Youtube and etc.

I know this question has been asked many times but after browsing the internet for a long time and getting more and more frusturated, I decided to ask for help myself.

My headset is HyperX Cloud Stinger although I don't think that they are the problem.
I'm also using a 3.5mm audio splitter from Deltaco. (this is kinda suspicious)

My Recording Properties:


My Playback Properties:


Device Manager:


I haven't installed Realtek drivers but I don't know if I should. I'm not sure if I'm using Realtek.

I probably should try this headset on some other Pc's or try to use different splitters. (I will update this to say if it works)
If anybody has any advice, please write because I'm getting desperate.