I'm sorry to hear that ☹️ it sounds like your partner may be abusive? Not sure, but if that's the case please do get the authorities involved.
From what you've said, it looks like your struggles are more internal than external. While it might be good for you to cut off your partner, you need to focus on your recovery. Do you have anyone who can support you with your Xanax addiction? Maybe you could apply for therapy. It seems like you need professional help. I think you might also be struggling with an ED, which could be a major reason for your feelings of depression and anxiety. As someone who has struggled with a minor ED, I've noticed that once I start eating 3 healthy meals a day and get some sunlight and exercise, it is easier to manage my anxiety (I've been in therapy for my anxiety twice without much help, this is the only thing that helped me pull myself out of the pit). I know it's easier said than done, but it is important for you to put some healthy structures in place. Maybe take a break from your partner, go no contact, work on yourself and make this decision.
If this is someone who has supported you through tough times, they might also be feeling burnt out from having to take care of you regularly. That could be the reason your relationship is feeling very stale.
I also wanted to say, scars heal. Scars don't make or break your face. Your beauty comes from the inside ❤️ I hope you get the professional help you need !