Whats wrong with this?

import java.awt.*;

import javax.swing.*;

public class GameScreen extends JPanel implements Runnable{

    private static final long serialVersionUID = 1L;
    public Thread thread = new Thread(this);

    private int fps = 0;

    public int scene = 0;

    public boolean running = false;

    Frame frame;
    Account account;

    public GameScreen(Frame frame){
        this.frame = frame;

        thread.start();
        Logger.log("Thread Started");
    }

    public void paintComponent(Graphics g){

        g.clearRect(0, 0, this.frame.getWidth(), this.frame.getHeight());

        if(scene == 0){ g.setColor(Color.DARK_GRAY); g.fillRect(0, 0, this.frame.getWidth(), this.frame.getHeight());}
        else if(scene == 1){
            g.setColor(Color.GREEN);
            g.fillRect(0, 0, this.frame.getWidth(), this.frame.getHeight());

            g.setColor(Color.GRAY);
            for(int x = 0; x < 27; x++) {
                for(int y = 0; y < 16; y++){
                    double width = (this.frame.getWidth() / (1920.0 / 1350.0)) / 27;
                    double height = (this.frame.getHeight() / (1080.0 / 800.0)) / 16;
                    g.drawRect(50 + (x * 50), 50 + (y * 50), (int) width, (int) height);
                }
            }
        }
        else {g.setColor(Color.WHITE);g.fillRect(0, 0, this.frame.getWidth(), this.frame.getHeight());}

        g.setColor(Color.YELLOW);
        g.setFont(new Font ("Calibri", Font.PLAIN, 30));
        g.drawString("FPS: " + fps, 5, 25);
    }

    public void loadGame(){
        account = new Account(this);
        running = true;
    }

    public void startGame(Account account){
        account.createPlayer();

        this.scene = 1;
    }

    public void run() {
        loadGame();

        long lastFrame = System.currentTimeMillis();
        int frames = 0;

        this.frame.addKeyListener(new KeyController(this));

        while(running){
            Logger.Update();

            frames++;
            if(System.currentTimeMillis() - 1000 >= lastFrame){
                fps = frames;
                frames = 0;
                lastFrame = System.currentTimeMillis();
            }
            repaint();
            try {
                Thread.sleep(5);
            } catch (Exception e) {
                Logger.logError("CANNOT SLEEP IN GAME LOOP!");
                e.printStackTrace();
            }

        }
        System.exit(0);
    }

    public class KeyTyped{

        public void keyQ(){
            Logger.log("Quitting Game");
            running = false;
        }

        public void keyF11(){
            Frame.devMode = !Frame.devMode;
            if(Frame.devMode) Logger.log("Dev Mode Active");
            else if (!Frame.devMode) Logger.log("Dev Mode Deactivated");
        }

        public void keySPACE(){
            startGame(account);
        }

    }
}