Microphone is recording stereo, not my input.

Hello,
I'm having some strange issues with my microphone.

ISSUE:
My microphone is not recording input at all. In fact, the only thing it IS recording is my stereo input (aka, what I hear from my earphones).

A day ago it was working properly, and then I attempted to stream my gameplay using Livestream.com's Procaster program. I THINK this is when things messed up, as afterwards when I attempt to speak to someone through voice chat I am instead just telling them whatever I'm hearing at the moment.

ATTEMPTS TO SOLVE:
I've thoroughly inspected my Control Panel settings and checked what's up with the microphone - I have four items there under the recording tab when managing my audio devices: "Internal AUX Jack", "Mic in the rear panel (Pink)", "Microphone (my laptop's internal microphone)", and "Stereo Mix". The odd thing I've noticed is that the volume bar for "Mic in the rear panel" goes up and down in tune with what I'm hearing. So far, fiddling with the options here does nothing.

I use Realtek HD Audio Manager and have updated it to the highest driver versions. I've checked the settings for this and am unable to find anything that can help me.