Don't be overwhelmed by your filing. Allocate 15 minutes per week to do as much as you can - whatever documents are left over... do next week!
If you can see your filing and it bothers you that it is not completed...create a new storage system! Get a basket with a lid or store it in a draw. Keep it out of your sight so you don't feel unproductive.
Filing is not the most fun part of any office environment but it is necessary to keep your office productive. Don't let it overwhelm you - only allocate 15 minutes per week.