Thanks Val78,
I have done a lot of self reflection and introspection on my issues that contributed to both the relationship breaking down and what prompted me to choose a relationship like that in the first place.
I think the hardest part for me is accepting that it wasn't actually all my fault that I wasn't the only one with issues. My self esteem plummeted dramatically after the relationship and I felt very defective always wondering what was wrong with me. My ex (as i'm sure a lot of others on here did) had an uncanny way of making everything my fault. Even when it was clearly obvious it wasn't I would come in with a sense that I knew I was in the right then by the end of the conversation I would feel like the bad guy. I remember one time when she showed me a photo of her hooking up with another guy, I rightly got angry about this and left to my parents for the day to get some space. Somehow that managed to get turned around onto me and it got made to be my fault and it was because I had gone and seen a friend that was a girl a few months earlier.
I suppose the last step in me detaching is accepting the fact that she had undiagnosed BPD and accepting the fact that it wasn't all my fault and that she was a long way from perfect. I know this intellectually I just have trouble really accepting it.
I've also been struggling with the fact that after 1.5 years I can still feel this way. I need to be a little kinder to myself about that and realize that it really isn't like a normal relationship breakup and the healing is a lot more in depth and a lot harder. I've also noticed at times when dealing with my various issues that they are in someone tied to the attachment that I still feel to my ex.
Hopefully some of that makes sense and doesn't seem like complete babble

Thank you for listening and helping me to see things from a different perspective.