Need help with headset setup

This is my setup, I have a turtle beach x12 headset connect to a mmf splitter to connect it to my pc and tv. My issue is that my microphone picks up audio from my tv, Strangely it doesn't pick it up from my pc. Please help me fix this.

The MMF splitters don't work for that.

Oh ok, is there any other way I can hear my TV and PC through my headset?