why don't you read everything in and then parse it once you get the enter key,
while(Serial.available() > 0) {
myChar = Serial.read();
currentLine += myChar;
if (myChar == '\n') {
int spacePosition; // the position of the next comma in the string
spacePosition = currentLine.indexOf(' ');
wordOne =currentLine.substring(0,spacePosition);
wordTwo =currentLine.substring(commaPosition+1, currentLine.length());
}
currentLine = "";
}