So, when I play a sound even if I never say anything into my mic on my headset then it plays the sound from the headset as if I was saying it on the game. I've tried turning the sound off and everything but it still picks up on it. Any ideas on how to fix it so the game only registers my voice and not the sound the PC is sending to play into my headset?
The solution would vary depending on what hardware you are using.
The most likely cause is that the 'microphone' you have selected in game is set to something along the lines of the 'what you hear' setting that sound blaster cards give.
Depending on your sound card and system configuration, you will want to select something that specifically mentions 'microphone' or 'line in'.