Uptown, your advice and suggestions and shared experiences have been very helpful in helping me to understand what I am dealing with. It doesn't make it any easier to detach though.
JPP, as a man who took 15 years to detach from a BPDer -- far longer than the 6 years you've been trying -- I can tell you that walking away is a very painful process for excessive caregivers like us. In addition to the childhood issues you mentioned, there are several other reasons for it being so difficult to leave.
The primary reason is that walking away from a BPDer feels like you are walking away from a sick young child who, despite her periodic tantrums, dearly loves you. Because a BPDer typically has the emotional development of a four year old, you likely will feel like you're abandoning a vulnerable young child. Although this feeling is very real and painful, you don't have to believe it.
It is simply not true that you are abandoning a child. Instead, you are allowing an emotionally stunted adult to confront the logical consequences of her own bad behaviors. If you choose instead to keep sheltering her from those consequences, your enabling behavior will harm her -- by destroying all incentives she has to confront her issues and learn how to manage them.
A second reason is that, whereas narcissists and sociopaths manipulate you with deliberate lies, a BPDer usually believes most of the outrageous allegations coming out of her mouth. Hence, because you know she loves you and truly believes most of her allegations, you mistakenly assume that -- if you can only figure out what YOU are doing wrong -- you can restore the R/S to that wonderful bliss and passion you saw at the beginning.
A third reason -- especially for excessive caregivers like you and me -- is that a BPDer relationship gives us an opportunity to experience the intoxicating feeling of being the nearly perfect man who has ridden in on a white horse to save the maiden from unhappiness. Our desire to be needed
far exceeds our desire to be loved
. We therefore are strongly attracted to a child-like woman who can project her vulnerability across a crowded room. Indeed, if you ever see a Marilyn Monroe movie, you will see a BPDer who could project enormous vulnerability right off of a flat movie screen.
A fourth reason is that, because a BPDer so completely mirrors the best aspects of your personality and your preferences, you both mistakenly believe that you have found your "soulmate." Hence, even when you later start to question that intense feeling intellectually, you still have to fight against the intense feeling that she is somehow perfect for you -- and destined to be your mate.