Who? Rin? He never said he loved her, Rin loved him but I'm not sure he loved her, was simply his friend.Kakashi had to kill someone he loved, Sasuke try to kill his friends for muh revenge.
And Sasuke killed people he loved as well, Itachi. He also had to watch people he loved (his father and mother) die in front of him not only once but many many times. He's gone through more than Kakashi that's for sure.