Meg I empathise with you so much. My mother too has BPD and it’s tragic the damage it wreaks. Going to therapy is the kindest thing you can do for yourself, it took me years to finally muster the courage. One of the most important aspects of the therapy is finally being validated for all the feelings and sadness that you’ve harboured for so long and been unable to communicate to others because they just simply wouldn’t understand. All too often I thought I was the one going crazy, but Mum’s behaviour was mixed with bouts of goodness / better moments of sanity.
I wish you well on your journey. All the best :-)