Audio stops playing after rtc is connected
The problem is 

repeat:
if(digitalRead(ProxSensor==LOW))
  goto repeat;


ProxSensor==LOW is false so 0. you read the pin 0 and the outcome is random. The surrounding wiring can affect that. If digitalRead(0) is zero the wav starts playing immediately again. At least use

while (digitalRead(ProxSensor) == LOW);