Missing space/Storage space running out Galaxy S2 [tried almost every solution I can find!]

I periodically get this error on my phone. It will say the internal storage is running out but when I check the storage use it will say:

Total space 1.97 GB Available: 182MB Apps: 622 MB Cached 11.70 MB

This time, I checked my android/data folder and it said Spotify was using 1GB of space (in addition to all the space it is using in my other storage), so I deleted the Spotify cache and uninstalled it, then wiped my cache in recovery, but I didn't end up with any extra space afterwards.

I've deleted the log and LOST.DIR folders.

I can't seem to free up any more space. Every time this happens I have to factory reset and reinstall cyanogen (I'm running CM 10.1.3 now) to recover storage space, but each time it happens again eventually. I tried updating to a newer version of CM 10.1.3 but that doesn't help either.

What am I doing wrong?

(Thanks!)