Just read the letter! Sky I think that is a fine idea to share that with her. She needs to know. What about starting a conversation about it so she gets to reply too? I would say "Can I ask you something? Why did you get so upset when I came in wearing headphones" so that way she knows that you get that you did something that upset her, but then you can also talk about what it meant to you. I hope she is empathetic this time around!!!! It is clearly a huge deal for you and your relationship.