This is not your average room condition and even if it is, there is no need to panic.
Step back, fight the urge to go to another room and then muster up your courage. It's easier if you are able to visualize how this area will look after you've tackled it. And addressing this kind of clutter doesn't mean doing it all at once. A multi-pronged and dedicated approach where you do a little bit at a time can produce wonderful results. Sorting through one pile of files and then the next and there are you are. You can start to relax and realize there really is light at the end of this tunnel and no train or car is coming at us from the other end!
Part of what often overwhelms us is the size of the problem. Yet just like we did those pesky math problems, we learned to take each piece and separate it so you could work on each element. We don't eat a whole meal in 2 minutes or even 20. Our stomachs would rebel if we tried that.
The same can be said about clearing out, sorting, letting go. It is a stage-based process that works best when we approach those piles and mounds from paper to kitchen items to closets with the concept of pulling out a small segment of the dreaded stuff and going slowly and without trepidation through what we see in front of us. Our project morphs into a manageable piece of business. We start first in that crossword of life with just the corner part of that puzzle. We take on first the "across" clues and move on to the "down" clues and wow! we have solved that section without pain or anxiety. It's a way to acknowledge what we are truly capable of doing to take back our space. Little by little, day by day. Week by week until we can look around and what we see engenders smile. Anxiety can be gone.