Rotate player based on custom axis

Ok, so I am making a game with some small planets the player can explore. Because the world is spherical, I had to make a custom gravity system. Anyway, I recycled some player movement code from an older project. The problem is that the way I coded the player to look around assumes it is on a flat world because it just rotates on the y axis. This will break the code that forces the player's feet to always face the ground, regardless of position on the planet. How can I modify this code?

     void Update()
     {
         GetInput();
         cam.transform.localRotation = Quaternion.Euler(xRotation, 0, 0);
         transform.localRotation = Quaternion.Euler(0, yRotation, 0);
     }
 
     void GetInput()
     {
         mouseX = Input.GetAxisRaw("Mouse X");
         mouseY = Input.GetAxisRaw("Mouse Y");
 
         yRotation += mouseX * mouseSensitivity;
         xRotation -= mouseY * mouseSensitivity;
 
         xRotation = Mathf.Clamp(xRotation, -85f, 85f);
     }

Here is a code snippet for the gravity

     void MovePlayer()
     {
         rb.rotation = Quaternion.FromToRotation(transform.up, (transform.position - planet.transform.position).normalized) * transform.rotation;
         rb.AddForce((transform.position - planet.transform.position).normalized * -10);
 
         rb.AddForce(moveDirection.normalized * moveSpeed, ForceMode.Acceleration);
     }

Any suggestions for improving either section would be greatly appreciated. I looked into the rotate around method but it does not seem like the right thing to use.