Your tone needs some work, like I understand that you're going for the whole Nirvana sound, but your tone is like pretty bad. The bassier notes sound really like floppy clean (almost like you're playing a noodle) and the bends seem to sound really off, my guess is that you have the action set way the frick too low. Secondly when you kick on the DS-2 it sounds kinda bad I'd recommend finding an amp with good distortion and just using that (line 6 and boss are both in my opinion crap for the most part). Furthermore, I'd say the "Nirvana sound" is actually more of an attitude than an actual sound cuz I run a fuzzface into an old magnatone and people LITERALLY ALWAYS tell me that my music reminds them of Nirvana. Also, think about this, would we have remembered Kurt at all if he was trying to sound like someone else? My guess is probably not, we remember him because of how he expressed himself through music. What I'm getting at is it is my opinion that you should use music to express yourself and you're kinda failing at that if you are trying to emulate the "Nirvana sound"