Why is my Unity screen glitching my items and not letting me see the 3D grid?

I’m a beginner to Unity, and I found a strange glitch in the scene. The scene window will not let me see the 3D Grid and every time I place an object, it puts at a random coordinates and gives me some kind of error. When I try moving the camera towards the item I placed, the screen glitches out and shakes around. I would provide video, but I don’t have any kind of capturing device/card/program. Note: This happened after I was just experimenting with Unity. I didn’t notice that this was happening until I pressed the 3D grid button and it did not work. Here is a picture of my Unity screen and what is wrong with it: http://i.imgur.com/rnzRl6m.png

1- Press the F key in your scene.
2- Change the values for transform of X, Y, and Z to 0,0, and 0.
3- Press F again.

4- If nothing works, try parenting it to a gameobject