Lost after our breakup

I am feeling really lost since my partner and I split a little over 3 months ago. She broke things off with me via text/email and was pretty no-contact with me at the end. Our relationship was so great. We got along so well and I still love her immensely. We had built and were building such a strong bond over the past few years and even her kids were telling me how much they loved me. I was all in with this relationship. I had a family and now they are gone. Long story short, I have struggled with chronic PTSD for most of my life. At the beginning of our last argument, I had an event and when faced with specific types of emotional triggers, I withdraw. I try my best to communicate, but it doesn’t always work. It had happened during the years of our relationship 3 other times. This time, I had an event and it really triggered a level of frustration my partner felt for me that I had not felt previously. She limited our conversations to text only, refused to see me and said some very hurtful things over the last few weeks of our relationship. I am certainly not absolved of any wrongdoing. I said some of the wrong things at the end and was not as responsive to a few situations or even as empathetic as I had been. It was weeks after the breakup until my psychologist helped me navigate through to understand that I was looking at the situation through the lens of my fear response. It’s not an excuse, but it helps to better understand what I was feeling and why. She has had some traumatic experiences relationally and I have to wonder if some of what happened between us opened an old wound for her? I’m not sure. At this point for myself, I am really struggling with low self worth and a really negative image. I entered treatment with a psychologist to better manage my triggers and deal with my PTSD, but I’m finding it painful and even a dishonor to the memory of my relationship with her to even think about moving on. It’s stalling the grieving process and it’s largely due to the lack of closure. Any advice is welcome. I appreciate the opportunity to share. Thank you.