Writing a letter of grievance against being asked for withdrawal

Hi guys,
Recently, I have been asked to withdraw from the school. I have already formed two appeals and both got (in ridiculous ways) rejected. Now I am being asked to form a grievance letter.
I would like to give you a brief information about why I am being kicked out and why i believe i should’t be.
I have not reached the GPA limit that is required for my program that does not even have a treshhold. I had some difficulties coping with my disabilities in my first year, later after i was diagnosed I had earned the right to not be kicked out the first year and continue my studies. Although my second year went well (not perfect), I was recommended by my psychiatrist to take the least course load as possible in the winter semester in order to maintain my mental health in the best way possible. So I did, even though I had realized it really was the best decision to do it unabled me to reach the required GPA due to the reduced amounts of credits.
I had an incline since the beginning of the school year, been working and playing varsity sports in the university and still managed to keep the incline. Plus, if I had knew they would kick me out because of this, i would have taken a bird course LIKE ALL THE OTHER PROBATION STUDENTS DO, RIGHT!? And spend all of the summer still taking courses.
Moreover, until the time for my diagnosis, the school has just been throwing me around and around and around until i finally made it to a doctor and start my therapies. During that time, i was sometimes randomly disabled to use my accomodations (WHICH WERE MY RIGHT IN ANY CASE) for exam taking and (genuinely) failed many courses because of it.
At this point it just looks like they dont want me and litterally either discriminate me because of my disabilities or nationality (which as a popular past of being stereotyped).

If you have any advises on how to write a grievance in a way to reach these people so they will be kinder, or anything else that you can think of please let me know.

Thank you for making so far to read,
Chlo
Edited out names of board members
ED