How do I get over the fact that my boyfriend of 6 years has a dog that was from an ex who traumatized me

I know I need therapy, and I’m currently saving up for it, but I really need some outside perspectives right now. This situation has taken a massive toll on my mental health, to the point where I recently resorted to self-h4rm out of sheer frustration that an innocent dog is bothering me this much.

I’m usually very self-aware, but I’m struggling to understand my own reaction here.

My boyfriend and I have been together for 6 years. During our first year, his recent ex heavily targeted me online. She harassed me, called me ugly, and spread rumors that he cheated on her with me (untrue, we met 10 months after their breakup). She constantly posted that he would leave me for her. At the time, my boyfriend reassured me, and we moved past it. We lived together for 4 years, but recently moved into separate homes due to work. Being alone has given me a lot of time to overthink.

The issue is the dog he got with his ex. I have always felt inferior to this dog. My boyfriend has told me that when the dog dies, he wants to die next—which makes me feel like I’m not a good enough reason for him to live. He wants his first tattoo to be of the dog. Worst of all, whenever we get into a fight, he changes his phone wallpaper from a picture of me to a picture of the dog, only changing it back once we make up.

All of this triggers memories of his ex’s posts. She once wrote that she "left her mark on everything he loved" and would "win in the end." I'm starting to feel like she was right.

I have tried everything to fix this. I adopted my own dog, bought him a puppy, and even babysat his dog for a month to try and bond, but the resentment won't go away. How do I handle this?

**TL;DR:** My boyfriend of 6 years shares a dog with his toxic ex, who used to harass me and bragged that she "left her mark" on him. My boyfriend's extreme attachment to this dog—like saying he'd want to die if it dies, and replacing my picture with the dog's when we fight—makes me feel completely inferior. It triggers my insecurities that his ex "won," and the situation is taking a severe toll on my mental health.