If I were grading this work, I wouldn't spend very much time on it trying to decipher your indecipherable handwriting.
You need to take the time to express your work in a clear, legible, organized way.
If your normal writing is sloppy (as mine is), then you need to take the time and put forth the effort to make it non-sloppy. It won't take long before it becomes your natural way of writing. I routinely receive complements on the neatness and legibility of my work, and each time I can't help but recall my days in junior high when it was anything but that. Fortunately, I had a teacher that returned my homework with a big zero on it, despite the fact that every single problem was worked correctly -- if you took the time to figure out what was actually written. She said that I could expect the same result going forward if things didn't change. I believed her. Things changed ... immediately.
Whether it's a grader in a college class, a customer or client, or your supervisor or management, you are generally providing a service for which the reader of your work is paying you -- whether it be with a grade, a sales, or a salary. The onus is on you to make them see it as being worthy of the price, otherwise they will just go elsewhere.
I had told him that a few times in the past, but he seems to not understand the importance of writing in a way that allows others to easily understand him.