_________ (Recipient details)
Subject: Apology for shouting
I hope you are doing well. I write this letter to apologize for shouting at __________ (shouted at) for _______________ (mention reason) on __/__/____ (date). I know that I shouldn’t have done this and should have behaved in a mature manner. Genuinely, I respect __________ (shouted at) a lot and whatever happened that day was not a reflection of my feelings for __________ (shouted at).
All this happened as I was frustrated for some reason. I feel sorry for the misbehaviour and ensure that I won’t be repeating the same again.
Your loving son-in-law/daughter-in-law,
___________ (mention your name here)