Can't Use System Menubar Javafx

I want to add a JavaFX Menu Bar to a Stage, but have it use the System Menubar for Mac.

My problem is that using:

menuBar.useSystemMenuBarProperty().set(true);

does not work. I believe that the problem is because my main method isn't part of a JavaFX Application. My main method looks like this:

public class SURPG_Launcher {

public static com.apple.eawt.Application macApp;

public static void main(String[] args) {
    if(Toolbox.isMac()) {
        initMac(args);
    } else {
        Application.launch(SURPG_Main.class, args);
    }
}

private static void initMac(String[] args) {
    System.out.println("MacOS System detected!");
    macApp = com.apple.eawt.Application.getApplication();
    macApp.setPreferencesHandler(new PreferencesHandler(){
    @Override
    public void handlePreferences(PreferencesEvent arg0) {
        Platform.runLater(() -> {
            Stage prefs = new Stage();
            prefs.setMinHeight(200);
            prefs.setMinWidth(200);
            prefs.show();
        });
    }
});

Application.launch(SURPG_Mac.class, args);

}
}

SURPG_Mac.class and SURPG_Main.class are classes that extend the JavaFX Application.

I have another class that sets the GUI, a stage with a BorderPane. I have another class with public static methods that can be called to set the Menubars, as such:

public class MenuControl {

public static MenuBar menuBar;
public static Menu menuFile;
public static Menu menuGame;
public static Menu menuTools;
public static MenuItem save;

public static void initMenusMac() {
    menuBar = new MenuBar();
    Platform.runLater(() -> {
        menuBar.useSystemMenuBarProperty().set(true);
    });
    menuFile = new Menu("File");
    menuGame = new Menu("Game");
    menuTools = new Menu("Tools");
    save = new MenuItem("Save");
    menuFile.getItems().add(save);
    menuBar.getMenus().addAll(menuFile, menuGame, menuTools);
    GUI_Main.totalLay.setTop(menuBar);
}

public static void initMenus() {
    menuBar = new MenuBar();
    menuFile = new Menu("File");
    menuGame = new Menu("Game");
    menuTools = new Menu("Tools");
    save = new MenuItem("Save");
    menuFile.getItems().add(save);
    menuBar.getMenus().addAll(menuFile, menuGame, menuTools);
    GUI_Main.totalLay.setTop(menuBar);
}
}

My final point is that I CANNOT change it so the main method is in either SURPG_Mac or SURPG_Main, due to a different compatibility problem with Mac integration.

Can anyone help me with this?

Thank you so much in advance!

Have a look at this probject: https://github.com/codecentric/NSMenuFX It allows you to have a more mac-like menu bar. But you will probably have to clean up your somewhat strange project setup as well before you can use it.