I know not about the settings of your particular camera. I just wanted to chip in a tip from my non-professional photography experience.
First, that's not a bad picture for a security camera, and a quite a good picture for a covert camera.
The resolution, colour is good given the lighting conditions. Since your TV watching area is dimmed and you are back-lit from the room behind you, its to be expected you and stuff around you is darkened. What you have is a lighting challenge, rather than a camera settings problem.
You can tinker with brightness in the settings but the room behind you will reach near white-out in order for you to get that darkened TV watching area to '18% grey' which is the mid-point of brightness cameras tend to adjust their aperture and shutter speed to reach.
Were the camera mounted in the bright room, but facing the darkened room without any light fixture in the frame, you'd have a much better exposure. Adding lights to the TV watching area of course defeats of the purpose of a TV watching area.
Another alternative is to leave the camera in the TV room but change the light shades on the fixtures on the room behind you to be opaque with only and opening at the bottom clear so to lessen the brightness that is causing the back-lighting. Since the camera is mounted much lower than those fixtures, it would need to be elevated to the height of the fixtures to not have direct light from the non-opaque opening at the bottom of the shade.