IntelliJ IDEA Creating a ton of new windows when I try to run my code

I'm making a very simple program in IntelliJ. It's going smoothly, and I would still be making progress if it ran properly. I click the run button and it gives me no errors when compiling, but it opens a ton of windows very quickly, and when I stop the program it closes them all. This has effectively halted my progress and I'm starting to run out of time to complete this. Anyone have a fix?

Code:

import javax.swing.*;
import javax.swing.border.Border;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
public class GUI implements ActionListener {
JFrame frame;
JPanel panel;
JLabel label;
public String output;
public String input;
public GUI() {
panel = new JPanel();
frame = new JFrame();
frame.setSize(500,400);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
frame.add(panel);
panel.setLayout(null);
label = new JLabel("Input");
label.setBounds(10, 20, 80, 25);
panel.add(label);
JTextField inputText = new JTextField(20);
inputText.setBounds(100, 20, 165, 25);
panel.add(inputText);
JLabel outputLabel = new JLabel("Password");
outputLabel.setBounds(10, 50, 80, 25);
panel.add(outputLabel);
JTextField outputText = new JTextField();
outputText.setBounds(100, 50, 165, 25);
panel.add(outputText);
JButton button = new JButton("Convert");
button.setBounds(10, 80, 80, 25);
button.addActionListener(new GUI());
panel.add(button);
JLabel successLabel = new JLabel("");
successLabel.setBounds(10, 110, 300, 25);
panel.add(successLabel);
frame.setVisible(true);
input = inputText.getText();
output = outputLabel.getText();
}
public static void main(String[] args) {
new GUI();
}
@Override
public void actionPerformed(ActionEvent e) {
}
}

Thank you for updating your post with the code. You have, in fact, created an endless loop!

The problem lies with:

button.addActionListener(new GUI());

You are creating a new instance of the class GUI every time the class GUI is instantiated. See what I mean?

I think you want to use the current instance of class GUI as your action listener, so the correct way to do this would be:

button.addActionListener(this);

Hope that helped.