Compelling personal reasons

Hi, if I upload it to my portal, do I do this before or after an application for this year? And do I still add a cover letter?
I was in a car accident a month before my course started that left me with physical pain and symptoms of ptsd as well as a bipolar diagnosis the year previous. I have a lot of evidence about the car accident and how it impacted me, but nothing from the university (they weren’t supportive) will this be enough or do I need stuff from the university?
I already have one completed year and one withdrawn year and I want to start a new course so need one year cancelled to be able to complete the new course.

Thank you!