Can't close position

I just started studying mql5 and i want to write a program that open a position at the opening of a bar and close it at the close(in 5M timeframe, so after 5 minutes).

for the opening there are no problems, but running the backtest i notice that it stops after opening the first order; can anyone tell me if there is something wrong in the close function?

void close(datetime open){ //function to close my position at the end of the candle in 5M timeframe

   bool close = true;
   MqlDateTime MyOpen, now;
   TimeToStruct(open,MyOpen);

   while(close){ // until the position is closed the function doesen't end
      TimeToStruct(TimeCurrent(),now);
      if(MyOpen.min == 55){ //i need to check the open minute because minutes are between 0/59
         while(close){
            if(now.min == 0){
               trade.PositionClose(0);
               close = false; // if the position is closed the loop ends
            }      
         }
      }   
      else if(now.min == (MyOpen.min+5)){
         trade.PositionClose(0);
         close = false;
      }      
   }

}