What you are describing is called dysgraphia. I have it too.
At my school my special needs coordinator has arranged for me to use a keyboard for my HSC courses, along with extra time. I was offered a writer/scribe for it too, but I turned that down for pride reasons.
My family took me to a specialist who works with dysgraphia and he gave me the best advice. Because most people hate writing lines and lines and lines of writing, treatment of that sort either becomes a chore or you start making excuses not to do it. I was one that chose the latter. This particular specialist picked up on it and instead of getting me in trouble and telling my family I wasn't being consistent with my practise he told them that he thought that copying out lines upon lines of writing is a poor way of trying to fix dysgraphia, because the person doing it gets extremely bored extremely quickly.
Instead of copying out pages of a textbook (which is what the first specialist told me to do) I was told to draw as much and often as possible, and told me to keep a loose schedule on it, as long as I draw at least two pages worth of drawings every two to three days I would gradually begin to improve. I could draw anything and everything I wanted. Characters and concepts for video games, animals, plants, weapons, anything I wanted. We went back to the specialist after three exercise books full of drawings, we repeated the dysgraphia tests and I had improved greatly in my ability to write and draw. Even today I draw two pages every two days.
The specialist's logic was that copying from a textbook never keeps people's attention and only improves the handwriting marginally. However, drawing is seen by the majority of people to be very fun thing to do, and keeps your attention. It became something I looked forward to instead of something to loathe.
It was during this time that I picked up creative writing (ie writing stories), which the drawing helped much more than copying notes, because drawing is like writing a story, just in visual form. Drawings constantly evolve, so do stories.
And my hands are starting to ache from typing so much, I may or may not follow this post up with more.
TL;DR: Drawing is better than writing.