god help me

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.Insets;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionListener;
import java.awt.event.MouseWheelEvent;
import java.awt.event.MouseWheelListener;
import java.awt.image.BufferStrategy;

import javax.swing.JFrame;

public class Pong extends JFrame implements Runnable, MouseMotionListener,
        KeyListener, MouseWheelListener {

    private int ballX;
    private int ballY;
    private int ballDX;
    private int ballDY;
    private int leftPaddleY;
    private int rightPaddleY;
    private int leftScore;
    private int rightScore;
    private BufferStrategy bufferStrategy;
    private Thread movePaddle;

    private static final int BALL_DIAMETER = 25;
    private static final int PADDLE_HEIGHT = 100;
    private static final int PADDLE_WIDTH = 10;
    private static final int WALL_OFFSET = 10;
    private static final int SCORE_OFFSET = 25;
    private static final int BALL_SPEED = 1;
    private static final int PADDLE_SPEED = 5;
    private static final Color BACKGROUND_COLOUR = Color.BLACK;
    private static final Color BALL_COLOUR = Color.WHITE;
    private static final Color PADDLE_COLOUR = Color.WHITE;
    private static final Color SCORE_COLOUR = Color.WHITE;

    public Pong() {
        super("Pong");
        this.setSize(400, 400);

        ballX = this.getWidth() / 2;
        ballY = this.getHeight() / 2;
        ballDX = ballDY = BALL_SPEED;
        leftScore = rightScore = 0;

        leftPaddleY = rightPaddleY = this.getHeight() / 2;

        this.getContentPane().setBackground(BACKGROUND_COLOUR);
        this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        this.addMouseWheelListener(this);
        this.addMouseMotionListener(this);
        this.addKeyListener(this);
        this.setVisible(true);

        new Thread(this).start();
    }

    public int verifyPaddleY(int y) {

        if (y < this.getInsets().top) {
            y = this.getInsets().top;
        } else if (y > this.getHeight() - this.getInsets().bottom
                - PADDLE_HEIGHT) {
            y = this.getHeight() - this.getInsets().bottom - PADDLE_HEIGHT;
        }

        return y;
    }

    @Override
    public void mouseWheelMoved(MouseWheelEvent e) {
        leftPaddleY += e.getWheelRotation() * PADDLE_SPEED;
        leftPaddleY = verifyPaddleY(leftPaddleY);
    }

    @Override
    public void keyPressed(KeyEvent e) {
        int dy = 0;
        if (e.getKeyCode() == KeyEvent.VK_UP) {
            dy = -PADDLE_SPEED;
        } else if (e.getKeyCode() == KeyEvent.VK_DOWN) {
            dy = PADDLE_SPEED;
        }

        final int arg = dy;

        if (movePaddle != null) {
            movePaddle.stop();
        }

        movePaddle = new Thread(new Runnable() {
            public void run() {
                while (true) {
                    leftPaddleY += arg;
                    leftPaddleY = verifyPaddleY(leftPaddleY);
                    try {
                        Thread.sleep(20);
                    } catch (InterruptedException e1) {
                    }
                }
            }
        });
        movePaddle.start();
    }

    @Override
    public void keyReleased(KeyEvent e) {
        movePaddle.stop();
    }

    @Override
    public void keyTyped(KeyEvent e) {
    }

    @Override
    public void mouseDragged(MouseEvent e) {
        this.mouseMoved(e);
    }

    @Override
    public void mouseMoved(MouseEvent e) {
        rightPaddleY = e.getY() - PADDLE_HEIGHT / 2;
        rightPaddleY = this.verifyPaddleY(rightPaddleY);
    }

    @Override
    public void run() {

        while (true) {
            Insets insets = this.getInsets();

            if (ballX < 0 || ballX > this.getWidth()) {
                System.exit(0);
            }

            if (ballX <= insets.left + WALL_OFFSET + PADDLE_WIDTH
                    && ballY >= leftPaddleY
                    && ballY <= leftPaddleY + PADDLE_HEIGHT && ballDX < 0) {
                ballDX = Math.abs(ballDX);
            } else if (ballX + BALL_DIAMETER >= this.getWidth() - insets.right
                    - PADDLE_WIDTH - WALL_OFFSET
                    && ballY >= rightPaddleY
                    && ballY <= rightPaddleY + PADDLE_HEIGHT && ballDX > 0) {
                ballDX = -Math.abs(ballDX);
                rightScore++;
            }

            if (ballY <= insets.top) {
                ballDY = Math.abs(ballDY);
            } else if (ballY + BALL_DIAMETER >= this.getHeight()
                    - insets.bottom) {
                ballDY = -Math.abs(ballDY);
            }

            repaint();
            ballX += ballDX;
            ballY += ballDY;
            try {
                Thread.sleep(5);
            } catch (InterruptedException e) {
            }
        }
    }

    @Override
    public void paint(Graphics g) {
        Insets insets = this.getInsets();
        super.paint(g);

        g.setColor(BALL_COLOUR);
        g.fillOval(ballX, ballY, BALL_DIAMETER, BALL_DIAMETER);

        g.setColor(PADDLE_COLOUR);
        g.fillRect(insets.left + WALL_OFFSET, leftPaddleY, PADDLE_WIDTH,
                PADDLE_HEIGHT);
        g.fillRect(this.getWidth() - insets.right - PADDLE_WIDTH - WALL_OFFSET,
                rightPaddleY, PADDLE_WIDTH, PADDLE_HEIGHT);

        g.setColor(SCORE_COLOUR);
        g.setFont(new Font("Arial", Font.BOLD, 20));
        g.drawString(String.valueOf(leftScore), this.getWidth() / 4,
                SCORE_OFFSET + insets.top);
        g.drawString(String.valueOf(rightScore), this.getWidth() * 3 / 4,
                SCORE_OFFSET + insets.top);
    }

    public static void main(String[] args) {
        new Pong();

    }

}