Hi Hazydays,
Welcome to the BPD Family
I'm glad you've decided to join the group. I have only one person with in my life with BPD/BPD Traits and that is my significant other's (SO's) undiagnosed BPD ex-wife (uBPDxw) and that is tough enough to negotiate, but dealing with several BPD people has got to be really tough. You've made a smart choice getting Therapy to support you as you negotiate your family members.

I've been in therapy for 34 years now and am viewed as the weakest link,... .
What I hear in this is you are not behaving in the (dysfunctional) way, or in the role, that your family wish you to fulfill so they criticize trying to bully you into the role they want you to be in. Don't listen to it, keep doing what you are doing.
Scary stuff. I want to escape but also want to be a part of my family and depersonalize the behaviors caused by low self esteem and false stories /gossip.
Mindfulness, I have to practice this when with my mother (not BPD but very critical). It's like being in the interaction but also outside of it like an observer. It helps the Panda in the interaction get the detached observations of the observer Panda.
So for example mom cuts me off when I'm talking... .as her daughter my feelings are hurt,I'm not being heard, I'm invalidated but the observer Panda will see that what I'm saying makes her uncomfortable, or embarrasses her, or makes her feel I'm a bad refection on her... .what do we have in common here? Her reaction is all about
her, it has nothing to do with me. I'm not uncomfortable about the topic, or embarrassed, and I'm not even thinking about how I reflect on her. Observer Panda tells me the reason she cut me off isn't about me at all it's about her. I am then able to not take it personally.
The other thing I wanted to share was to try not to JADE (Justify, Argue, Defend, Explain). Jading will just continue the drama, you can end up in circular arguments that go no where or even end up escalating the drama. I know this is hard to do, it does take practice. But if you don't JADE you don't feed the drama and the conflict. You do not owe anyone an explanation for what you decide to do.
More on Mindfulness... .
https://bpdfamily.com/message_board/index.php?topic=64749.0More on JADE... .
https://bpdfamily.com/message_board/index.php?topic=139972.0You might also think about boundaries that you set around what kind of behaviors you will and will not accept from your family members. Build a strategy before they arrive.
I look forward to hearing what other members have to share with you. That is the strength of this site all of the perspectives of the members here. Everyone "gets it" and there is a wonderful combined wisdom of the folks here. I'm glad you've added your voice and your experience to the group.
Take Care,
Panda39