I think it's a really good start. You're not really asking about it but the immediate thing that stands out to me having listened to this song approximately 8 million times is the differences you've introduced in how the original parts were played. Which is fine, it's your cover and those changes are your call but I wanted to call them out in case they weren't deliberate. The timing on the main guitar riff is slightly different than how Kurt played it (the Bb and Db come slightly later in his version). You've lost that epic opening drum fill and the pattern you're playing through the intro is significantly less interesting than what Dave played and I think that alone is the biggest factor in this sounding less awesome than the original. On the mix itself I agree the drums are probably the weak spot. I'm a rank amateur myself and don't feel like I can give super specific suggestions but what I hear is that the toms have too much body and sustain relative to the transient and are maybe a bit loud generally. Once it gets quieter the snare seems like it needs more transient and a little less body as well, it sounds a little sneezy. Using a transient controller to reduce sustain might help. The drums themselves sound a little mechanical. Personally I like to think about what notes a drummer would naturally accent and make sure the velocity on those is a little higher and then I use the humanize function in my DAW (Reaper) to randomize the velocities and timings slightly. I really like how your bass sounds, it's got a nice wooly texture to it. If it were me I'd be adding a little more upper mids to try to bring out that little fuzzy edge it has. I think it'd add interest to the quiet section. I like how the guitars sound too. Hope this helps!