Should call it a day but hanging on in there just?

[Cliffton]

Have been with my partner now for coming up to 4 years and she's an undiagnosed, but I would say 100%, sufferer of BPD. Absolute 100%.
We've recently split (I asked her to go this time) as her behaviour has been getting worse and worse since her last return. She leaves about once a year but then when she returns it doesn't take long for the splitting cycle to return and I become all bad, hated and "the narcissist".
This latest term of living with me has lasted only a few months with her behaviour being terrible for most of it, except for a 10 day stretch in the middle when we were on holiday out of the country and she was perfection.
I know I should "give it up" but I don't because I hang on to the hope she'll get help and the good times will increase - when we're good its the best and I love her more than I've ever loved anyone. We're both 50 plus and I'm 7 years older...
Everyone tells me I should leave it and give up on her but it's obviously not that easy when you know they're suffering even more and that the condition is an illness and not just intentionally bad behaviour. Not entirely sure what I'm after in response - I just wish things were different and I could wave a wand but that's never happening...

[RELATIONSHIP PROBLEM SOLVING]

RELATIONSHIP PROBLEM SOLVING This is a high level discussion board for solving ongoing, day-to-day relationship conflicts. Members are welcomed to express frustration but must seek constructive solutions to problems. This is not a place for relationship "stay" or "leave" discussions. Please read the specific guidelines for this group.

[Cat Familiar]

Knowing what you know, and having had the repeated experience you’ve had, what are the positives in the relationship that outweigh the negatives?

Has she expressed any interest in getting therapy?

[Cliffton]

The positives are based on when she’s good she’s the best partner, friend, soul mate I’ve ever had and the only woman I’ve ever truly loved - to be honest I didn’t think I’d ever find real love or if it existed. She’s also got a good relationship with my son apart from the fact he obviously witnesses her mood extremes. As for therapy she has tried to get help, I’ve been with her to the GP but they were useless and treated it very glibly - no diagnostic tests or anything - just have her a leaflet on yoga and a course of sertraline. Sometimes she’s accepts she’s got a problem but at other times it’s all down to me - the narcissist

[AdRock]

I feel you that when things are good, they are amazing.  The best advice is to remember two things.  They cannot help who they are and they are not choosing to hurt you.  If she is willing to one day get help, there may be hope because people with bpd are not bad and many can have relationships of some fashion.  Beyond that, focus on yourself and ultimately do what is best for your own mental health.  It sucks and I am going through it myself but that is all you can ultimately do.