letters = new JLabel[26];

for (int i = 0; i < 26; i++) {
    int ch = 'A' + i;
    letters[i] = new JLabel("" + (char) ch);
    panel.add(letters[i],c);
}
ctrl.setLetters(letters);

public void setLetters(JLabel[] letters2) {
    letterLabel = letters2;
    for (int i = 0; i < letters2.length; i++) {
        letterLabel[i].addMouseListener(this);
/* i'm assuming this issue is here with adding tons of mouselisteners to the label each time it resets, but i'm not sure how to fix it */
    }
}

@Override
public void mousePressed(MouseEvent e) {

    for (int i = 0; i < 26; i++) {
        if (e.getSource() == letterLabel[i]) {
            if    (!game.letterAvailable((letterLabel[i].getText().charAt(0)))){
                letterLabel[i].setText(" ");
            }
            else {
                game.makeGuess((letterLabel[i].getText().charAt(0)));
            }
        }

    }

    update();
}

public void update() {
    if (letterLabel != null) {
        setLetters(letterLabel);
    }
    if (panel != null) { // redraw (not important for this error)
        panel.repaint();
    };
}