Why is my instructions JLabel not displaying properly? The text either stays horizontal or turns into a narrow column. Can someone help me solve this issue please?

package pkgCarInsuranceCalc;
import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
public class Instructions extends JFrame{
JLabel lblInstructions = new JLabel();
    public Instructions(){
        super("Instructions"); // frame title
        // adding and setting panel
        JPanel panel = new JPanel(new GridBagLayout());
        panel.setBackground(Color.WHITE); // panel background colour
        GridBagConstraints gbc = new GridBagConstraints();
        gbc.insets = new Insets(10,10,10,10);
        // label for instructions
        lblInstructions.setText("<html><span style='font-size:15'>" +
                        "Want to know the average premium costs from around " +
                        "the country?<br>Then this calculator can help.<br> " +
                        "Just select your area, age, sex and claims from the " +
                        "menus, press 'Calculate', and you'll be presented " +
                        "with the current average premium.<br>The prices " +
                        "calculated should be treated as a rough guide only. " +
                        "<br>There are plently of other factors which are " +
                        "likely to affect the premium you pay - such as make " +
                        "and model of car, and convictions history and so on.");
        gbc.gridx = 0;
        gbc.gridy = 10;
        panel.add(lblInstructions, gbc);
} // end of Instructions class