There are websites galore devoted to writing a proper letter in Japanese. For example, if you don’t know what to say to your own mom on Mother’s day, there is this sample letter: http://www.midori-japan.co.jp/letter/bunrei/1552
That left me wondering if we have the same thing in English. When I wrote my mother her card for Mother’s Day, I wrote from the heart, but surely isn’t there a PROPER way to do it? So I searched the internet and found this: http://www.foundletters.com/personal-letters/sample-mothers-day-greeting-letter/
You always loved and cared for me since my childhood. I still remember you would hide my mistakes from Dad to save me from his anger. You would take the blame on you for many of my mistakes in home. You would not tell Dad about my poor grades in school.
This person needs more help than a sample letter can provide.