Writing letters you never intend to send can be a great way to express and expel the anger. It’s so important you burn that anger off so that you can get yourself strong and healthy no matter the outcome of your relationship with her.
What resonates with me is how frequently she is talking about being bored and needing the unexpected (to the point that she is self destructive). Based on the family molestation and incest I suspect she is a chaos kid. If you aren’t familiar with this, look into it. These are adults who feel most comfortable in the same chaos that was swirling around them as children. Calm, peaceful environments are actually unsettling to them because they are unfamiliar. They misread it as boring.
Until they face it, they will create chaos because it’s familiar and comfortable.
You are doing great. Keep feeling what you are feeling. You will get through this.
Me 41, H 47, M 15 yrs, S11, S13 BD 1: 11/4/14 we work on it; really I pretzel myself BD 2: 3/31/15 H goes down to "dorm room" 8/15: H back to MBR 10/15: H back in dorm room 1/18: H files, now divorced