Main camera attached to player is being "Weird"

So, basically, I have done nothing to almost anything in the past hour. Now that I have returned to do things, I placed a cube, gave it a rigid body, so it became a physics object, now, my players camera has begun to SLOWLY sink downwards, I deleted the cube and its still sinking…

First thought to come to mind: gravity.

Rigidbody automatically applies a gravity affect to anything that it is attached to. You may want to turn off the gravity in the rigid body component to stop your objects from sinking.