Freeze Character control on axis

Is there a way to freeze the charactercontroller.Move on one axis at a time? For example if I wanted to ignore gravity when I call a function.

I created a FirstPersonController script (I followed Quill18's simple fps tutorial):

 //Floats
         //Movement Speed
         public float movementSpeed = 5.0f;
         public float mouseSensitivity = 2.0f;
 
     //Rotation
         float verticalRotation = 0f;
         public float UpDownRange = 90f;
 
         float verticalVelocity = 0f;
         public float jumpSpeed = 2f;
 
     //Character Controller
     CharacterController cc;
 
     // Use this for initialization
     void Start () {
         //Character Controller
         cc = GetComponent<CharacterController>();
 
         if(cc == null)
         {
             //Freak Out
             print("No Character Controller");
         }
 
 
         //Lock cursor
         Cursor.lockState = CursorLockMode.Locked;
         Cursor.visible = false;
     }
     
     // Update is called once per frame
     void Update () {
     //Rotation
         //GetAxis
         float rotX = Input.GetAxis("Mouse X") * mouseSensitivity;
         verticalRotation -= Input.GetAxis("Mouse Y") * mouseSensitivity;
 
         //RotateRangeUpDown
         verticalRotation = Mathf.Clamp(verticalRotation, -UpDownRange, UpDownRange);
         Camera.main.transform.localRotation = Quaternion.Euler(verticalRotation, 0, 0);
 
         //RotateLeftRight
         transform.Rotate(0, rotX, 0);
 
     //Movement
         //GetAxis
         float h = Input.GetAxis("Horizontal") * movementSpeed;
         float v = Input.GetAxis("Vertical") * movementSpeed;
 
         //Vector speed
         if (!cc.isGrounded)
         {
             //Gravity
             verticalVelocity += Physics.gravity.y * Time.deltaTime;
         }
 
         Vector3 speed = new Vector3(h, verticalVelocity, v);
         speed = transform.rotation * speed;
 
         //Jump
         if (cc.isGrounded && Input.GetButtonDown("Jump"))
         {
             verticalVelocity = jumpSpeed;
         }
 
         //Move
         cc.Move(speed * Time.deltaTime);

I tried having 3 booleans (LockX, LockY and LockZ) and having if statements saying that if one of them is locked, the speed vector has 0 on that axis. For example:

 if(LockX)
 {
     speed.x = 0;
 }

But I couldn't get it to work..

Any idea why and what I could do different?