I’d tell anyone to write the letter and then sit on for at least a week. Maybe you have sent it already though. I don’t know your exact situation but sometimes we write in anger and sometimes a few days go by and we revisit things and change our minds. It sounds like maybe someone is controlling or bossy? I also believe like you do that no one has the power over me, that we have the power within ourselves. You don’t sound like an awful person writing this out on here. Sometimes venting helps. Sometimes we have to learn to distance by saying no or hanging up the phone or walking away. Some people don’t take no for an answer and it becomes a power struggle just to hang on to our agency. I have to say that bossy or controlling or mean people can upset me alot. Best wishes to you.