First Person Head Bobble Issues

 var head:CharacterController;
 var toTheRight = false;
 function Start(){Bobble();}
 function Bobble(){
     while(true){
         if(head.isGrounded  && head.velocity.magnitude > 3){
             var camera = GameObject.FindWithTag("MainCamera");
             if(toTheRight == false){
                 for(var i=0;i<100;i++){ //goes to the top-right
                     camera.transform.position += Vector3(0.001,0.001,0);
                     yield WaitForSeconds(0.0001);
                 }
                 toTheRight = true;
             }
             else if(toTheRight == true){
                 for(var ix=0;ix<100;ix++){ //goes back to original pos
                     camera.transform.position -= Vector3(0.001,0.001,0);
                     yield WaitForSeconds(0.0001);
                 }
                 for(var ixx=0;ixx<100;ixx++){ //needs to go to the top-left
                     camera.transform.position -= Vector3(0.001,0.001,0);
                     yield WaitForSeconds(0.0001);
                 }
                 toTheRight = false;
             }
         }
         else{yield;}
     }
 }

You know how there are head bobbling whenever you walk? Well I'm having some issues:

-It will head to the top right at first, but then hit left more and more and then get back up to the right, but it will keep going "lefter" and lefter, which is because I cannot think of how to phrase the Vector3 line where I put the comment "needs to go to the top-left" -Not just this, but when you stop moving, the for loop will still continue and I cannot think of a way to get around that and make it stop immediately. -It's also an incredibly unrealistic head bobble movement and I'll need improvement for it

Can anybody help fix this mess please? Or a link where I could freely find a good head bobble movement for first person? It would be great. Thanks.