I remember getting notices from financial aid and school that the suspension policy and appeal process had changed this last year. Unfortunately however, I could not find on their website how to go about doing this. I would contact the school, as Perna mentions above, to find out how to go about doing it and as Christina mentions, get documentation from your medical providers to support your withdrawal as well for this part of your appeal. There may be particular forms or formats though that they require, so find out first before you contact your physicians.
This summer I might have had to withdraw due to medical and the school said financial aid would have been suspended because of it. It could be appealed on those grounds though with medical documentation. I would definitely be in contact the school's financial aid office and get who I need to be in contact with to get the information I need to file.
I hope you are feeling better. Wishing you all the best and GOOD LUCK!