And mom says she had not had contact with him in x years, since ___, has no idea where he is, does not know anyone who does. The things you told us. That she is your sole support, etc. If she doesn’t know where he is, she shouldn’t guess. (!)
Don’t confuse the college. It’s trying to understand. Just providing piecemeal info only prolongs.
Your HS GC probably had her name only on your records, right? Call the hs. Get this done. Get a note from the doc, sure. But get this done.