For a JavaFX MVC application, How can I reference model from controller, to avoid using statics

Question

I'm sure this is fairly simple and I am misunderstanding something. I have a controller class linked to an FXML(view). The controller does not contain any statics, yet when I try and reference the model like this:

 @FXML
 public void goToConvert(MouseEvent event){ 
     myController.setScreen(GameModel.CONVERT_SCREEN); 
     GameModel.CONVERTB = true;
     GameModel.PLAYB = false;
     GameModel.COMPAREB = false;
     GameModel.SETTINGSB = false;
     GameModel.HELPB = false;
     GameModel.ProcessSreeenSwitch();

GameModel is my model
CONVERTB is a public boolean
ProcessScreeenSwitch() is a public void

Without taking any measures to include an object reference to GameModel in the controller, every line using GameModel creates the common error:

non-static variable CONVERTB cannot be referenced from a static context

Even though there are no statics in the controller whatsoever. I don't understand why the current context is static. I have tried declaring GameModel as an object above e.g (in the same place as ScreensController myController is declared in the code at the bottom)

 GameModel GameModel = new GameModel();

or

 GameModel GameModel;

These measures stop the static error but create a NullPointerException when they are called. For example, if goToConvert is called the NullPointerException is at the line:

GameModel.CONVERTB = true;

How can I make the current context non-static to change the values in the GameModel from the controller.

Cheers

Lucio

Controller Class:
    package aimdot;

import java.awt.MouseInfo;
import java.awt.Point;
import java.io.File;
import java.net.URL;
import java.util.Random;
import java.util.ResourceBundle;
import java.util.concurrent.TimeUnit;
import javafx.event.ActionEvent;
import javafx.fxml.FXML;
import javafx.fxml.Initializable;
import javafx.scene.Group;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.Label;
import javafx.scene.image.Image;
import javafx.scene.image.ImageView;
import javafx.scene.input.MouseEvent;
import javafx.stage.Stage;

public class PlayScreenController implements Initializable, 
                                            ControlledScreen { 

     ScreensController myController; 
     //final static Image MOUSECURSOR = new Image (PlayScreenController.class.getResource("MouseCursor").toString());
     //final static Image MOUSECURSOR_IMAGE = new Image (PlayScreenController.class.getResource("MouseCursor").toString());
    // final static Image MOUSECURSOR_IMAGE = new Image (PlayScreenController.class.getResource("MouseCursor").toString());
    @FXML
    private ImageView imageView;
     @FXML
    private ImageView MouseCursor;
      @FXML
    private ImageView RectangleMouseHolder;
       @FXML
    private ImageView Target3Rings;
        @FXML
    private Label PLAYBUTTON;


     @Override
     public void initialize(URL url, ResourceBundle rb) {


            } 


     public void setScreenParent(ScreensController screenParent){ 
        myController = screenParent; 
     }   

     @FXML 
     private void PLAYBUTTONPressed(MouseEvent event){ 
     PLAYBUTTON.setTranslateX(-400);
     GameModel.AnimationTargetStart();
     PLAYPHASE();
   } 
    @FXML
    public void TargetMissed(ActionEvent event){ 


   }


     @FXML
    public void goToPlay(MouseEvent event){ 
     myController.setScreen(GameModel.PLAY_SCREEN); 
     GameModel.CONVERTB = false;
     GameModel.PLAYB = true;
     GameModel.COMPAREB = false;
     GameModel.SETTINGSB = false;
     GameModel.HELPB = false;
     GameModel.ProcessSreeenSwitch();
   } 
     @FXML 
     private void goToMain(ActionEvent event){ 
     myController.setScreen(GameModel.MAIN_MENU); 
     GameModel.CONVERTB = false;
     GameModel.PLAYB = false;
     GameModel.COMPAREB = false;
     GameModel.SETTINGSB = false;
     GameModel.HELPB = false;
     GameModel.ProcessSreeenSwitch();
   } 


    @FXML
    public void goToConvert(MouseEvent event){ 
     myController.setScreen(GameModel.CONVERT_SCREEN); 
     GameModel.CONVERTB = true;
     GameModel.PLAYB = false;
     GameModel.COMPAREB = false;
     GameModel.SETTINGSB = false;
     GameModel.HELPB = false;
     GameModel.ProcessSreeenSwitch();
   } 

    @FXML
    public void goToCompare(MouseEvent event){ 
     myController.setScreen(GameModel.COMPARE_SCREEN); 
     GameModel.CONVERTB = false;
     GameModel.PLAYB = false;
     GameModel.COMPAREB = true;
     GameModel.SETTINGSB = false;
     GameModel.HELPB = false;
     GameModel.ProcessSreeenSwitch();
   } 

   @FXML
    public void goToSettings(MouseEvent event){ 
     myController.setScreen(GameModel.SETTINGS_SCREEN);
     GameModel.CONVERTB = false;
     GameModel.PLAYB = false;
     GameModel.COMPAREB = false;
     GameModel.SETTINGSB = true;
     GameModel.HELPB = false;
     GameModel.ProcessSreeenSwitch();
   }        

   @FXML
    public void goToHelp(MouseEvent event){ 
     myController.setScreen(GameModel.HELP_SCREEN); 
     GameModel.CONVERTB = false;
     GameModel.PLAYB = false;
     GameModel.COMPAREB = false;
     GameModel.SETTINGSB = false;
     GameModel.HELPB = true;
     GameModel.ProcessSreeenSwitch();
   }  

    @FXML
    public void MouseLocation(MouseEvent event){ 

   }
    @FXML
    public void RestartButton(MouseEvent event){ 

       GameModel.RestartRound();

   }




 public void PLAYPHASE(){
     boolean targetSpawned = false;

     GameModel.playPhase = true;


     long gameStartMS = System.currentTimeMillis();
     long gameStartS = TimeUnit.MILLISECONDS.toSeconds(gameStartMS);


     }


 }

EDITED for addition steps tried.

tried using

 GameModel Model = new GameModel();

in each controller, and eliminating use of GameModel fromt he controller but it didn't work. It still creates a null pointer exception at

Model.ProcessSreeenSwitch(); 

In GameModel class:

public void ProcessSreeenSwitch(){
        System.out.print("PlayB: "+PLAYB);
        if (PLAYB == false){
            target.setVisible(false);
            PlayLabel.setVisible(false);
            PutMouseMiddle.setVisible(false);
            hitCountG.setVisible(false);
            missCountG.setVisible(false);
            rectangleMouseBoxG.setVisible(false);
           RestartPlayButton.setVisible(false);
           PlayTimer.setVisible(false);
           PlayTimerText.setVisible(false);
        }
        if (PLAYB == true){
            target.setVisible(true);
            PlayLabel.setVisible(true);
            PutMouseMiddle.setVisible(true);
            hitCountG.setVisible(true);
            missCountG.setVisible(true);
           rectangleMouseBoxG.setVisible(true);
           RestartPlayButton.setVisible(true);
           PlayTimer.setVisible(true);
           PlayTimerText.setVisible(true);
        }
    }