Glad you have time to read, reflect, rewrite and so forth.
If in the end, giving him the letter will hive you the peace of mind that you have done EVERYTHING humanly possible to save your M, then is say you'd win the lottery. . For now though, take the time you have and then make a decision later. . Maybe a "miracle" will happen before then, maybe the "cosmos" will speak to you in a different way. Now I may be being "too new-agey". . Hang in there and keep us posted.
. For now though, take the time you have and then make a decision later. 
. Maybe a "miracle" will happen before then, maybe the "cosmos" will speak to you in a different way. Now I may be being "too new-agey". 