Thanks for your extended reply Dr Jackie, it really is helping me (I have been borderline suicidal for the past month).
I suppose a pressing issue for me is whether, although I tried my best, ***** ***** have been stronger, set more boundaries etc. Whether, had I not expressed that weakness, things would have lasted for longer?
It's interesting that you mentioned early experiences. Her parents broke up when she was young, possibly due to cheating. Her father then cheated on another partner. However, her step-father and mother have always been a stable partnership. Her sisters are not like her at all either - both are kind, respectful, in very long term relationships. But she feels inferior to both of them.
It's interesting that you describe her behaviours as selfish - from the inside of this, I keep finding excuses for her - tempatation, pressure, low self-esteem for cheating, then awkwardness, guilt, uncertainty for the manner of the breakup. But I suppose that this can't be justified on this basis? She doesn't seem like the kind of person I would want to end up spending my life with.
This immaturity showed itself at other times, but not always. I wonder whether she will grow out of it? Do you think her behaviours could be suggestive of character flaws rather than immaturity?
The other thing I wanted to ask about was her behaviour since the breakup. I barely heard from her for 2 months and removed her from facebook. When she realised, she asked me why by text. I told her I was seeing someone new and she responded with "Now my head has gone into overdrive" and "I hope she makes you as happy as you made me". What does this indicate?
Finally, I had a severe car accident recently (a suicide attempt although noone is aware of this). When she heard of this she immediately called me and, following a text conversation, we met up. This seems to indicate caring, but is not consistent with her previously selfish behaviour. Would love to know what you think.