Instead of using your whichletter int, you could just use the cntl int that you are using to control your for loop. This should insure that your number is incrementing.
Also, in your if statements
if (guessedletter.charAt(whichletter) == wordchosen.charAt(whichletter))
{
right++;
}
I think it should be
if (guessedletter.charAt(0) == wordchosen.charAt(whichletter))
{
right++;
}
Unless I am mistanken, the guessedLetter is overwritten each time and only contains a single character correct?