Remove the delay(5000) at the bottom of loop(). You are reading 1 character every 5 seconds, causing the SoftwareSerial input buffer to overflow constantly. You will need to check to see if there is data available on SoftwareSerial, since you took out the while() that tests for that.
It would also help to significantly increase the baud rate of Serial, otherwise the amount of time you spend waiting to send text will also cause the SoftwareSerial receive buffer to overflow.