Taking a little break from everything to try and do some recording again. Apart from still not being able to get a good guitar sound, I'm having problems with the clearness of chords when I play them.

Like, the bass sounds are really drowning out the higher notes and so it just becomes really fuzzy. And in my songs I use kinda big chords, as in, they're not just power chords. I'm guessing this could be fixed with EQs or something? But I don't know much. Hope I'm making sense, help?
The easiest way to clear out low-end mudiness in guitars is to use a high pass filter in your EQ plug in.
This is a screen shot of how to do it in Reaper I took for another user: http://dl.dropbox.com/u/16210823/eq.png

What a high pass filter does it roll off frequencies below your set threshold, allowing only higher frequencies to pass. Experiment with different thresholds, the idea is to clear the mud while still keeping the tone beefy. A lot of guitar mud is around 100-150hz.
You can also try doubling the guitar tracks. This means play and record what you record twice and pan them hard right and left (You can also experiment with other panning). This gives me the clarity of my chords and has a less fizzy sound that you are experiencing.
Is the High Shelf filter in the EQs in Cubase LE4 the same thing? Because it kinda works, but I lose too much thud from the lower strings now.

And I tried double tracking too which kinda helps. But then my Cubase gets all shit and basically crashes. Don't quite know why, maybe my computer can't handle so many tracks. So I can't really double track, but is there anything else I can do?
A high shelf is not what you want, that will just boost every frequency above the threshold. A general rule of thumb with EQing is making cuts is better than making boosts.
Ahh right. I don't quite know what making cuts/boosts are, but I'm just assuming it's going plus or minus on the EQ thing? Is there something similar to what you've got in Reaper in Cubase? I'm exporting a single guitar track right now so I can put it in Reaper but it's quite long, or is there any decent free plug-ins you would suggest?