Why is my camera motion so jittery?

I have been working on trying to smooth out my camera motion for my game for days and I cannot get it to a reasonable level of smoothness. Are there any corrections to this code that I can make that will improve the smoothness? I have tried the moveTowards() function as well and it didn't help.

/ CAMERA MOVEMENT */

 void FixedUpdate () {
             //Do we need to spawn new platforms yet? 
             Vector2 playerHeight = playerTransform.position;
             if (playerHeight.y > nextPlatformCheck) {
                     PlatformMaintenaince (); //Spawn new platforms
             }
     
             //Update camera position if the player has climbed 
             Vector2 currentCameraHeight = transform.position;
             
             if (playerTransform.position.y > currentCameraHeight.y) 
             {
             transform.position = Vector2.Lerp(new Vector2(transform.position.x,0.0f), new Vector2(0.0f, playerHeight.y), smooth * Time.deltaTime);
             } 
             else {
                     // If player is too low, gameover.
                     if ((playerHeight.y) < (currentCameraHeight.y - 5.5)) {
                             GameOver();
                     }
             }
     }