Jittering Camera 3D ,Jittery 3D camera using a LookAt() on an object

I have a simple project that I'm working on for school coursework and I'm using a LookAt() at the object. However, when I rotate move the camera the object jitters horribly. I've looked on the forums and tried solutions but I can't find anything. I'll post the code as well as the video. Thank you all for your time!

 public class CameraMovement : MonoBehaviour
 {
 // Start is called before the first frame update

 public Transform target;
 public float rotationSpeed;
 public float normalFOV;
 public float zoomedFOV;
 public int smooth;   

 void Start()
 {
     normalFOV = 100f;
     zoomedFOV = 10f;
     rotationSpeed = 10f;
     smooth = 5;
     this.GetComponent<Camera>().fieldOfView = normalFOV;
 }

 // Update is called once per frame
 void FixedUpdate()
 {

     transform.LookAt(target);
     if (Input.GetMouseButton(1))
     {
         MouseRotation();
     };
     MouseZoom();      
     
 }

 private void MouseRotation()
 {
     Vector3 cameraV = new Vector3(
         Input.GetAxis("Mouse X"),
         Input.GetAxis("Mouse Y")
         );
     
     transform.Translate(cameraV * Time.deltaTime * rotationSpeed);
 }

 private void MouseZoom()
 {
     if (Input.GetAxisRaw("Mouse ScrollWheel") > 0f && this.GetComponent<Camera>().fieldOfView != zoomedFOV)
     {
         this.GetComponent<Camera>().fieldOfView -= smooth;
     }
     if (Input.GetAxisRaw("Mouse ScrollWheel") < 0f && this.GetComponent<Camera>().fieldOfView != normalFOV)
     {
         this.GetComponent<Camera>().fieldOfView += smooth;
     }
     }

Video Link

,I have this simple camera that I use to focus on an object. However, every time I do rotate it, it causes really jittery camera movement. I will paste the code I've used for the camera below.

 public class CameraMovement : MonoBehaviour
 {
 // Start is called before the first frame update

 public Transform target;
 public float rotationSpeed;
 public float normalFOV;
 public float zoomedFOV;
 public int smooth;   

 void Start()
 {
     normalFOV = 100f;
     zoomedFOV = 10f;
     rotationSpeed = 10f;
     smooth = 5;
     this.GetComponent<Camera>().fieldOfView = normalFOV;
 }

 // Update is called once per frame
 void FixedUpdate()
 {

     transform.LookAt(target);
     if (Input.GetMouseButton(1))
     {
         MouseRotation();
     };
     MouseZoom();      
     
 }

 private void MouseRotation()
  {
     Vector3 cameraV = new Vector3(
         Input.GetAxis("Mouse X"),
         Input.GetAxis("Mouse Y")
         );
     
     transform.Translate(cameraV * Time.deltaTime * rotationSpeed);
 }

 private void MouseZoom()
 {
     if (Input.GetAxisRaw("Mouse ScrollWheel") > 0f && this.GetComponent<Camera>().fieldOfView != zoomedFOV)
     {
         this.GetComponent<Camera>().fieldOfView -= smooth;
     }
     if (Input.GetAxisRaw("Mouse ScrollWheel") < 0f && this.GetComponent<Camera>().fieldOfView != normalFOV)
     {
         this.GetComponent<Camera>().fieldOfView += smooth;
     }
 }
 }

I will also attach a video to demonstrate the problem.

Video Link

Thank you very much for your time and I tried to search the forums but I couldn't find anything to help me, I had already tried to use FixedUpdates etc, it may be just that the code isn't really optimum. Again, thank you very much!