Hi there f10a
I'm really sorry to hear of the hard time you are having right now
My relationship was actually with someone who had both BPD & NPD. It ended this time last year. I see that you have been pointed to the areas of this site where you can read up, to help you determine which condition(s) your gf may have. Both of these conditions are within the Cluster B Personality Disorders, category, along with several others there. It is common for someone with 1 of these conditions to have others from that category. It's referred to as being co-morbid.
The only way to know which condition your gf has, other than her having being diagnosed by a professional, is via reading up on the conditions. They can have many behaviours in common, and so it's not always easy to know.
Unless a person with one or both of these personality disorders chooses to seek professional help, and then sticks to it long-term, the changes required in the relationship, generally come from us nons. You talk about wanting to get your gf to see X or Y, or learn to do things such as compromise. If she's not getting regular therapy because she wants to change, then I'm afraid you can try to do all of that until you're blue in the face, but it rarely works.
We can learn to implement a set of techniques, which basically changes the way we respond to our loved one's behaviours. It is down to us to change ourselves to better the situation. There are lots of lessons and suggestions here on this site, which really can make a huge difference, but these take much practice, strength and determination on our part. It is really hard work, but we can see some really positive results when we get the knack.
What you need to ask yourself, is that if your gf does not want to change (and if the narcissistic side is strong, this may well be the case, because people with NPD tend to see everyone else to be the problem, and not their behaviours), are you prepared to spend the rest of your time together modifying your approaches & responses, in order to better the communication? Can you be happy in a relationship where your gf continues to act in the ways that you describe, and you act as a care-giver in order to moderate her behaviour. Some people choose to do this, and can significantly improve things to make life more tolerable. Often these are people who already have children with their partner who has a pd, and feel it is something they want to do for that reason. It's a very personal decision that only you can make, and no one here would want to try to sway you to do anything other than what you want to do.
My own experience was that the narcissistic side of my ex was far too strong for him to ever seek treatment. He would say when he was in his BPD frame of mind, that he knew he needed help, but then later (sometimes that same day) he would switch back to NPD and deny ever saying he needed to seek help, because it was me (or whoever else applied) that needed treatment. There was no emotional support from him, because he had no ability to empathise, and so I never had someone to take the weight, as we all need from time to time. I was a full time care giver, and I felt as though I had a small child rather than a partner.
When I was ill, he was too wrapped up in his own 'problems' (usually very trivial things) to want to help me. I just decided that I wanted a bf who could play an equal role... .be a partner.
Long-term, you may also want to consider things such as if you would like a family. If it is something you would like, then I would suggest having a read of some of the posts over on the Parenting board. Children are often severely affected by a NPD/BPD parent.
It's a lot to think about and to take in. I would advise taking time to read through experiences of other members here, and also reading the lessons and other material here on this site. It's hard to know what you want to do in a situation, until you know what you are dealing with, and what can be done. If you read through the lessons and learn about the techniques to deal with behaviour, such as S.E.T., and feel that you don't want to be in a relationship that requires you to be a care-giver, then perhaps you may want to view your gf's want to be out of the relationship, as a way out, yourself. The change of mood from being head over heels in love one week, and feeling like she wants out of the relationship the next, is common in relationships with a pd person. It is likely that you will see that happen in future. There is a lack of middle-ground for people with such conditions, as you describe... .it's black or white... .bad or good. It can be pretty exhausting!
You will get a great deal of support from the members here on this site, whatever you decide to do. You are not alone in this, as we all understand
Hugs,
JP
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