Arduino Pro Mini with AA batteries

Thank you guys - it sounds like there must be something really wrong with my wiring. I do use the super low power sleep in my code. The unit only goes on to send one NRF24 packet and then stays asleep for 20 minutes.

  // read sensor data
  // send through NRF 24
  radio.powerDown();
  digitalWrite(TS_PIN, LOW); // TS_PIN is connected to the transistor base
  delay(100);

  Debugln("Starting sleep");
#ifdef DEBUG_MODE
  int sleep_time = 0;
#else
  int sleep_time = (success == 1) ? SLEEP_CYCLES_SUCCESS : SLEEP_CYCLES;
#endif

  for (int il = 0; il < sleep_time; il++)
    LowPower.idle(SLEEP_8S, ADC_OFF, TIMER2_OFF, TIMER1_OFF, TIMER0_OFF,
                  SPI_OFF, USART0_OFF, TWI_OFF);

  Debugln("Sleep completed");

This is my diagram. To prevent the sensor to be powered on all the time I use a 2N3904 transistor to gate the power delivery to both my NRF24 and my sensor. Would anyone have a better suggestion?