Arduino UNO Dimming Zero Cross SSR Code HELPPP

My lights are not dimming.... I don't know what to do. I think it is my code.

unsigned char AC_LOAD = 9;    // Output to Opto Triac pin
unsigned char dimming = 3;  // Dimming level (0-100)
unsigned char i;


void setup() {
  // put your setup code here, to run once:
  pinMode(AC_LOAD, OUTPUT);// Set AC Load pin as output
  attachInterrupt(2, zero_crosss_int, RISING);

  // Serial.begin(9600);

}

void zero_crosss_int()  // function to be fired at the zero crossing to dim the light
{
  // Firing angle calculation : 1 full 50Hz wave =1/50=20ms 
  // Every zerocrossing : (50Hz)-> 10ms (1/2 Cycle) For 60Hz (1/2 Cycle) => 8.33ms 
  // 10ms=10000us
  
  int dimtime = (100*dimming);    // For 60Hz =>65    
  delayMicroseconds(dimtime);    // Off cycle
  digitalWrite(AC_LOAD, HIGH);   // triac firing
  delayMicroseconds(8.33);         // triac On propogation delay (for 60Hz use 8.33)
  digitalWrite(AC_LOAD, LOW);    // triac Off
}



void loop() {
    
       
           
        
          for (i=5;i<85;i++)
          {
            dimming=i;
            delay(20);
          }
        
          for (i=85;i>5;i--)
          {
            dimming=i;
            delay(20);
          }
                     

}

Here is my ZCD Schematic and the SSR board I am using.

what lights?

The variable dimming is used in the loop function and in the interrupt service routine and therefore should also be declared volatile.

There may be other issues as well.