Not sure why you think you can't do anything with the drums. That should be the first place to start. Get your drums sounding good before doing anything else. Turn off all the other tracks and just work on drums. No guitar, no bass, no vocals ( I know there are no vocals in this particular song).
Midi or not, you can do a lot with the drums. Mostly, it seems to be EQ adjustments, or simply removing anything you've done to them already. They might sound good wothout any adjustments at all. Depends on what you are using as a sound source for the drums.
Headphones and laptop speakers are horrible to mix on, but there are ways around it. Listen to a lot of commercial recordings similar to the style of your song. And I mean listen a lot. Switch back and forth between your song and one that is similar. Listen to the differences and try to recreate that feel. Listen to each instrument. Start with just drums, then add bass, then add guitars. then add vox.
Guitars should only be there to support the bass and drums. Don't make them the dominant instrument.
What everyone here said is good advice. But take all that one bean at a time, don't go for the whole enchilada on the first go around.