HID keyboard with toggle switch

Hello everyone i'm a new user for arduino
I'm building a F-16 cockpit simulator but i have a problem
I have an Arduino Uno and i changed its hex codes to emulate HID Keyboard just like that:

Now i have keyboard but i have to use toggle switches instead of buttons
I need to have one keyboard char at a time
Like semi automatic guns instead of full auto
Here is my test circuit

And here's the code

/* Arduino USB Keyboard HID demo
 * Cut/Copy/Paste Keys
 */

#define KEY_LEFT_CTRL  0x01
#define KEY_LEFT_SHIFT  0x02
#define KEY_RIGHT_CTRL  0x10
#define KEY_RIGHT_SHIFT 0x20

uint8_t buf[8] = { 
  0 };  /* Keyboard report buffer */

#define PIN_C 5
#define PIN_X 6
#define PIN_V 7

int state = 1;

void setup() 
{
  Serial.begin(9600);

  pinMode(PIN_C, INPUT_PULLUP);
  pinMode(PIN_X, INPUT_PULLUP);
  pinMode(PIN_V, INPUT_PULLUP);
  // Enable internal pull-ups
  
}

void loop() 
{
  int sensorVal = digitalRead(5);
  state = digitalRead(PIN_X);
  if (state != 1) {
    buf[0] = 0;
    buf[2] = 27;    // Letter X
    Serial.write(buf, 8); // Ssend keypress
    releaseKey();
  } else {
    delay(5);
  }

  state = digitalRead(PIN_C);
  if (state != 1) {
    buf[0] = 0;
    buf[2] = 6;    // Letter C
    Serial.write(buf, 8); // Send keypress
    releaseKey();
  } else {
    delay(5);
  }

  state = digitalRead(PIN_V);
  if (state != 1) {
    buf[0] = 0;
    buf[2] = 25;    // Letter V
    Serial.write(buf, 8); // Send keypress
    releaseKey();
  } else {
    delay(5);
  }

}

void releaseKey() 
{
  buf[0] = 0;
  buf[2] = 0;
  Serial.write(buf, 8); // Release key  
  delay(500);
}

Can you solve my problem? Thanks

Additional: Here is the keyboard codes:
http://scriptel.com/KeyboardEmulationAPI/JavaScript/tutorial-Keyboards.html

Now i have keyboard but i have to use toggle switches instead of buttons

So you have to use the state change rather than just the state.

That means triggering he key when the button becomes pressed not when it is pressed. To do this you have a last state variable for each switch and trigger when the current state is zero and the last state was one.