In general, blurring destroys information. The information is lost, no algorithm can recreate the original picture out of a blurred one unless it can somehow "guess" the information needed to do this.
A "sharpening" algorithm (as available in most graphic manipulation programs like GIMP or Photoshop) does not really create an unblurred version of the picture but instead only changes the existing blur in a way so that our eyes have the feeling that the picture is sharp (mainly by increasing local contrasts). If you look closely you will see a lot of artifacts which would still not be very readable.
You have a picture of text only; in this case it might be possible for an algorithm to figure out which character is meant (using OCR) and then make a new picture out of all recognized characters. For this it could use any font you like of course. This would still lose all details the algorithm did not recognize (e. g. accents, commas, dashes, etc.).
But in your case the quality of the picture is so bad that I don't think any algorithm would be able to help you. The (quite dark) lines which were already on the paper before it was written to also pose a problem for this approach. OCR algorithms don't handle such things very gracefully.
I fear in your case you are stuck with what you have. Maybe you can work with it if you only look at a zoomed part of your picture to avoid overstraining your eyes.