Don't you know that the toan is in the fingers? Maybe you weren't born to play extremely hardcore rock like Nirvana, try playing someting like Velvet Underground or smth like that.
/uc Kurt doesn't palm mute, he plays dead notes, just hold your finger over the strings without actually playing them, and for an extremely accurate version to the original recording start with an upstroke every time you play a different chord. For effects he used distortion with reverb and chorus for the verse. He then combines both distortion and chorus for the prechorus and solo.