Here is a post that I saw on this topic from someone who was on a committee that review Appeal letters:
My committee would consider you a strong case for reinstatement if you can provide:
a) documentation from your health care provider of a diagnosis
b) confirmation from your health care provider that you have been compliant with treatment and your situation has improved so that you are better equipped to handle the stress of college life if/when you return
c) details of how you plan to continue your treatment plan after you return to school
d) details of other campus resources you will use and adjustments you will make after you return to enhance your success
e) some statement of how you know your treatment has improved your situation (e.g. if you have been working during your time away and found it easier to handle the stress and demands as your treatment progressed)
So the most important thing is to get your health in order.
You can ask for a retroactive medical withdrawal.
I agree to have your parent help with a leave of absence request.
When you are healthy, then worry about the appeal letter.
yes, that may mean you may not go back in the next semester…but you may not be ready to.