Player Controls Upside Down

 public class Gravity : MonoBehaviour
 {
     private float g = -9.81f;
     private bool gravity = true;
     Character player;
     GameObject avatar;
     // Start is called before the first frame update
     void Start()
     {
         player = GameObject.FindGameObjectWithTag("Player").GetComponent<Character>(); 
         avatar = GameObject.Find("Rainboy");
     }
 
     // Update is called once per frame
     void Update()
     {
         Physics.gravity = new Vector3(0, g, 0);
         if(Input.GetKeyDown(KeyCode.G)){
             if(gravity)
             {
                 gravity = false;
                 print(Physics.gravity);
             }
             else if(!gravity)
             {
                 gravity = true;
                 print(Physics.gravity);
             }
         }
 
         print(g);
 
 
         if(!gravity)
         {
             g = 9.81f;
             player.gravity = false;
             //player.chara.position.y += 1.5f;
             //pos.y = 1.5f;
             //Physics.gravity = new Vector3(0, 9.81f, 0);
         }
         else if(gravity)
         {
             //player.rig.velocity = new Vector3(player.x,player.rig.velocity.y,player.z);
             player.gravity = true;
             g = -9.81f;
             //Physics.gravity = new Vector3(0, -9.81f, 0);
         }
     }
 
     void OnTriggerEnter(Collider other)
     {
         Physics.gravity = new Vector3(0, g, 0);
         if(gravity){
             gravity = false;
         }
 
         else{
             gravity = true;
         }
     }
 
 public class Character : MonoBehaviour
 {
    [HideInInspector]
     public float x;
     [HideInInspector]
     public float y;
     [HideInInspector]
     public float z;
 private bool dead = false;
 private float angle = 0;
 void Update()
     {
         if(!dead){
         x = Input.GetAxis("Horizontal") * moveSpeed;
 
         z = Input.GetAxis("Vertical") * moveSpeed;
 
         y = Input.GetAxis("Jump") * moveSpeed;
 
         }
 
         if(!dead)
         {
             rig.velocity = new Vector3(x,rig.velocity.y,z);
         }
         else
         {
             rig.velocity = new Vector3(0,0,0);
         }
         
         Vector3 vel = rig.velocity;
         vel.y = 0;
 
         if(vel.x != 0 || vel.z != 0){
             transform.forward = vel;
         }    
 
         if(gravity)
         {
             StartCoroutine(GDelay());
         }
         else if(!gravity)
         {
             StartCoroutine(ZeroGDelay());
         }
     
 if(jump == true){
     if(Input.GetKeyDown(KeyCode.Space) && isGrounded == true){ 
         isGrounded = false;
         if(gravity){
             rig.AddForce(Vector3.up * jumpForce, ForceMode.Impulse); 
         }
         else if(!gravity)
         {
             rig.AddForce(Vector3.down * jumpForce, ForceMode.Impulse); 
         }
         //AudioListener.volume = 1.0f;
         if(on == true){
             jumpSound.mute = false; 
             jumpSound.Play();
         }
      }
 }
 }
 
 public IEnumerator ZeroGDelay(){
     yield return new WaitForSeconds(0.5f);
     angle = 180;
 }
 
 public IEnumerator GDelay(){
     yield return new WaitForSeconds(0.5f);
     angle = 0;
 }
 
 }

The rest is pretty self-explanatory. I want to be my character walk around upside down, but everytime they move it flips them right-side up