Hi Sunny86,
That is quite an emotional rollercoaster ride you have been on, so sorry to hear about this !
However you came to the right place for knowledge and support, so may I give you a warm welcome to BPD Family ?

If I read it correct, you're the caretaker of the family, trying to keep the family together. I understand this must be a really hard situation, and one must not forget to take care of one's self as well.
So instead of looking first to the rest of your family, I would like to ask you what support you have in this situation ? Do you have a family, friends in supportive ways to deal with all of this ?
I already see one positive thing in what you write, that is that are making boundaries on what you accept on the behavior of the loved ones who may have borderline, and that is a good thing. Borderline or not, they have to know that there are lines that can not be crossed. It is hard for them to understand this sometimes, but you have every right to do so.
This may be an interesting thing to read on the matter and how to make things a bit better :
Supporting a Loved-one with Borderline Personality DisorderI saw you mentioned a number of books you've been reading on BPD, may I ask you which ones ? Did any of these include advice on how to deal with the behavior of someone with borderline ?
Hang in there, we are here to help !
Reg