Hi Joem678,
you ask a tough question.
Why does she always drop the relationship and come back? What happens to her?
people with BPD are,... well people. yes they have a disorder. yes the disorder plays out in very similar ways but it's very hard to speculate as to why anyone does anything.
I personally think it's even harder when you are dealing with some one whose communication skills can be rudimentary at best. the communications you get can sometimes be misleading.
BPD traits include an unstable sense of self. This one is the hardest for me to 'see' in my partner.
According to Margalis Fjelstad's who is an expert in this field an unstable sense of self looks like this.
Intense fear or paranoia about being rejected, even to the extent that they need to be approved of by people they don't like. If I can make so and so fall in love with me I must be lovable.
Often change their persons, opinions or beliefs, depending on who they are with. If Jane Smith likes chocolate ice cream and I think Jane is wonderful I will like chocolate ice cream too and hence be wonderful also.
Lack of a consistent sense of self of who they are, or may have an overly rigid sense of self. On Tuesday I will never ever go to that bar again, and on Friday... .
Often present a facade. May be fearful of being seen for "who I really am." Automatically assuming that they will be rejected or criticized.
Out of sight, out of mind... difficulty realizing that they or others exist when not together.
Simultaneously see themselves as both inferior and superior to others.
It is very hard to understand how they process life.
'ducks