Realistic head moving on walk

"Amnesia: Machine for pigs"s mechanics inspired me. I made a simple picture, explanation of my idea. I used this code http://wiki.unity3d.com/index.php?title=Headbobber and tryed to think of an idea to make camera go:

(Explained on the picture) Up and left, down to more left, then up back to the top while going right and down while going right again, then repeat last step backwards and repeat last 2 steps and loop them, --but moves back to old ( 0, +2, 0 ) position.

But I want to make it end when not on the ground (Jump, fall...)...I think I can make it follow the movement speed and also stop and chrouch a little bit on fall from jump, because I have fixed movement in the direction I jumped.

PS. I am making horror game in which is important to keep the experience that the player is not controlling character, but he is in the game. -Maybe someone will make a little effort to help me if I say that I will not publish unfinished game or crappy looking like you can see on internet and indie game sites...

I will be trying to make it work by myself but all help is welcome, especially when it can help someone else or make new physic movement script. :D