&gt; **I know she loves me too.**

If your GF is a pwBPD, she is capable of  loving you very intensely but it is the very immature type of love you see in young children.  This means she will occasionally flip -- in   only  ten seconds -- from Jekyll  (adoring you) to Hyde (devaluing or   hating you).  And a few hours or days later,  she can flip back again  just as quickly.   These rapid flips arise from a childish behavior  called *"black-white thinking."*

Like  a  young child, a pwBPD is too emotionally immature to be able   to   handle   strong conflicting  feelings (e.g., love and hate).  This    means  she   has great difficulty tolerating ambiguities, uncertainties,    and the  other gray areas of  close interpersonal relationships.

She  thus will  subconsciously split off the conflicting  feeling,   putting  it far out of  reach of her conscious mind.  With young children, this  "splitting" is  evident when the child will adore Daddy while he's  bringing out the  toys  but, in only ten  seconds,  will flip to hating  Daddy when he  takes one  toy away.

Importantly,  this behavior does  not  mean that the child has  stopped loving Daddy.   Rather, it means  that her conscious mind is temporarily out of touch  with those loving feelings.

Similarly, a  pwBPD  will  categorize everyone close to her as  "all  good"  (i.e.,  "white" or  "with me") or "all bad" (i.e., "black"  or  "against me").   And she will  recategorize someone from one polar extreme to the other  -- in just ten seconds -- based solely on a  minor  comment or action.

This   B-W  thinking also will be evident in her frequent use of    all-or-nothing  expressions such as "You NEVER..." and "You ALWAYS...."   Because her close friends eventually will be "split black," it  is   unusual  for a BPDer to have any really close *long-term* friends (unless they live a long distance away).  

&gt; **I  understand how rough depression is.**

If she actually does have BPD, she likely has 2 or 3 co-occurring "clinical" disorders as well.  A 2008 American study found that 80% of female pwBPD have a co-occurring mood disorder like depression and 81% have a co-occurring anxiety disorder.  See Table 3 at [2008 Study in JCP](http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2676679/).

&gt;**She has sought help in the past, but she didn't think it was effective and has not sought help again after.** 

By its very nature, BPD symptoms are invisible to nearly all pwBPD.  This is why BPD is said to be "ego-syntonic," i.e., the behavioral symptoms are in such complete harmony with needs and desires of the ego that the pwBPD regards them as normal and useful.  It thus is rare for a high-functioning pwBPD to remain in a therapy program long enough (many years) to make a real difference in her behavior.

&gt;**I genuinely love her and I think she's an awesome person.** 

If your GF really is a pwBPD, she very likely is "an awesome person."  A pwBPD's problem is not being BAD but, rather, being UNSTABLE.  Most pwBPD exhibit the warmth, sponteneity, vulnerability, and purity  of expressions that otherwise are seen only in young children.  

As  any parent can tell you, young children are VERY EASY to fall in love  with.  It thus is not surprising that two of the world's most beloved  women -- Marilyn Monroe and Princess Diana -- both had full-blown BPD if  their biographers are correct.

Indeed, it is this childlike behavior that makes most pwBPD very hard  to walk away from.  Because you are essentially in a parent/child  relationship, leaving is so painful because it feels like you're  abandoning a young child who -- despite her frequent temper tantrums and cold sulking --  must dearly love and need you.