Multiplayer updates are really slow

This is hard to explain, and will seem like block text at first, and for that I apologize. I'm working on a multiplayer shooter.

All of the movement and turning in-game are really slow to the other players in the game, but they are responsive to the player moving, i.e. if I turn, it is really slow and has a lot of drag if you're looking at it, but on the client-side screen it's a normal speed. When a projectile is fired, and the firer is currently rotating, it will fire one of two ways:

A) If it is the LAN host firing the bullet, it will go normally, but other players will see it as firing from a location way before the host even turns to that place.

B) If it is a joining player, they will fire bullets, but they will fire in the direction that they just rotated from, usually about a second before. However, for the host, it looks completely normal.

I have all of the rotation, firing, and movement handled in one huge master file, in C#, so I'm just going to put the whole thing below. Any help is appreciated.

using System.Collections; using System.Collections.Generic; using UnityEngine; using UnityEngine.Networking; using UnityEngine.UI;

public class PlayerController : NetworkBehaviour {

 public float speed = 2.0f;
 public float jumpHeight = 5.0f;

 public float mouseSensitivity = 100.0f;
 public float clampAngle = 80.0f;

 private float rotY = 0.0f;
 private float rotX = 0.0f;

 public float bulletCooldown = 0.5f;
 private float bulletTime = 2.0f;
 private float bulletDoubleTime = 0.0f;
 public int bulletSpeed = 20;

 public GameObject bulletPrefab;
 public Transform bulletSpawn;
 public Transform secondBulletSpawn;

 public const int maxHealth = 100;

 [SyncVar(hook = "OnChangeHealth")]
 public int currentHealth = maxHealth;

 public RectTransform healthBar;

 void Start()
 {
     Vector3 rot = transform.localRotation.eulerAngles;
     rotY = rot.y;
     rotX = rot.x;
     Cursor.visible = false;
     bulletDoubleTime = (Time.time / 2) + bulletCooldown;
 }

 void Update()
 {
     if (!isLocalPlayer)
         return;

     float fire = Input.GetAxis("Fire1");

     float x = Input.GetAxis("Horizontal");
     float z = Input.GetAxis("Vertical");
     float y = Input.GetAxis("Jump");

     x = x * Time.deltaTime * speed;
     z = z * Time.deltaTime * speed;
     y = y * Time.deltaTime * jumpHeight;

     transform.Translate(x, y, z);

     //rotation

     float mouseX = Input.GetAxis("MouseX");
     float mouseY = -Input.GetAxis("MouseY");

     rotY += mouseX * mouseSensitivity * Time.deltaTime;
     rotX += mouseY * mouseSensitivity * Time.deltaTime;

     rotX = Mathf.Clamp(rotX, -clampAngle, clampAngle);

     Quaternion localRotation = Quaternion.Euler(rotX, rotY, 0.0f);
     transform.rotation = localRotation;

     //firing

     if (fire > 0 && Time.time > bulletTime)
     {
         CmdFire();
         bulletTime = Time.time + bulletCooldown;
         return;
     }

     if (fire > 0 && Time.time > bulletDoubleTime)
     {
         CmdDoubleFire();
         bulletDoubleTime = Time.time + bulletCooldown;
         return;
     }
 }

 void OnChangeHealth(int currentHealth)
 {
     healthBar.sizeDelta = new Vector2(currentHealth, healthBar.sizeDelta.y);
 }

 [Command]
 void CmdFire()
 {

     // Create the Bullet from the Bullet Prefab
     var bullet = (GameObject)Instantiate(
             bulletPrefab,
             bulletSpawn.position,
             bulletSpawn.rotation);

     // Add velocity to the bullet
     bullet.GetComponent<Rigidbody>().velocity = bullet.transform.forward * bulletSpeed;

     // Spawn the bullet on the Clients
     NetworkServer.Spawn(bullet);

     // Destroy the bullet after 2 seconds
     Destroy(bullet, 2.0f);
 }

 [Command]
 void CmdDoubleFire()
 {

     // Create the Bullet from the Bullet Prefab
     var bullet = (GameObject)Instantiate(
             bulletPrefab,
             secondBulletSpawn.position,
             secondBulletSpawn.rotation);

     // Add velocity to the bullet
     bullet.GetComponent<Rigidbody>().velocity = bullet.transform.forward * bulletSpeed;

     // Spawn the bullet on the Clients
     NetworkServer.Spawn(bullet);

     // Destroy the bullet after 2 seconds
     Destroy(bullet, 2.0f);
 }

 public override void OnStartLocalPlayer()
 {
     GetComponent<MeshRenderer>().material.color = Color.red;
 }

 public void TakeDamage(int amount)
 {
     if (!isServer)
     {
         return;
     }

     currentHealth -= amount;
     if (currentHealth <= 0)
     {
         currentHealth = 0;
         Debug.Log("Dead!");
     }
 }

}