Hello and welcome to the family. I'm so sorry you're in this situation and I wish there was a way to "fix this" so it doesn't continue. Unfortunately though, BPD can't be fixed unless someone is ready to put in considerate time and effort in therapy. Even before that though, they have to realize that the problem within their life actually comes from within.
But to admit that to yourself as a mentally ill person when there's zero answer on how to overcome it...it's almost impossible. For that reason, your mom deserves compassion. What she says and does is genuine since she believes it wholeheartedly. Why? Because the actual truth is too much to bear- every failed relationship came from her sabotaging everything good in her life.
I remember a time my BPD daughter sprained her ankle. It was a bad sprain and the doctor told her to move around as little as possible for a month, to wear boots that supported the ankle, etc. But instead, my kid wore flip flops and ran/jumped every oportunity she had. As a result, a short term injury became like a two-year cycle of anger, blame, sympathy plays....even though there was a clear way to fix things. Just do what the doctor said, what everyone is telling you. Just let it heal. But she simply refused to be told what to do.
Your mom is in the exact same position, she needs to mentally heal through therapy. But instead, she leans on you for emotional support while trying to destroy anything in your life that gets in the way. That's why your parents' marriage failed, and it could be why your marriage eventually fails as well. It is manipulation at its finest.
I said all of that to say this- you are responsible for you. Mom is responsible for mom. When that no longer feels true, it's time to take a few steps back. I do agree with you that mom needs your endless compassion and empathy to function, but once you begin to withdraw, she will simply find someone else to fill that void. She's done it her entire life. This is not your job though and it's not your responsiblity.
Push back on her narratives surrounding your childhood, but at the same time make it crystal clear, "I love you but I will not talk about this anymore. It is emotionally draining." If she respects that, great. If not, hang up and distance yourself for a few days. Then rinse and repeat.
Do this exact same thing when it comes to your job, your partner, your lifestyle, your family, etc. If this is to be a mutual relationship, then you get some say in what you actually talk about and your feelings should be respected. The one-way relationship has to end though, there's nothing in it for you but harm and emotional trauma.
This plays out one of two ways- either mom learns to respect your boundaries, or you end up no contact. The only one who can change this dynamic is you though, and your healthy boundaries will drive her one step closer to admitting the ugly truth- she's seriously ill and needs to take therapy seriously. Letting her dominate your life has the exact opposite effect; there's no need to change anything if she gets her disordered emotion support from you.
You have to choose one path- either you're in charge of you, or mom's disordered thinking is.



