Welcome Chania: Congrats on your pregnancy

I'm sorry about the problems you have with your sister.
I have a sister that is 2 years older than me and have problems with her as well. Sorry to hear that therapy isn't going well for her.
My sister has gotten antidepressants from her primary care doctor, but that's the extent of her treatment. She indicated, before we went to no contact, that her doctor suggested she get counseling. Her position was that she didn't need counseling. As many times seems to be the case, someone else in the family goes for therapy to try and figure out what is going on. It took me going to therapy to learn that my sister is likely a high-functioning BPD.
When she rages she is vile, swears at me and my mom and brings out the worst in me where I was doing the same to some extent because I couldn't get my point across.
Same with my sister. The rage starts, she gets into name calling, goes down a long list of everything she has ever disliked about you (can seem like from the beginning of time, ). I now understand that the only thing to do is remove your self from the situation and don't engage. It's a "no-win situation" until some time has passed and the rage passes.
Anyways it's hard to not feel guilty that I am wrong as she comes across as so sweet and charming to everyone else,even to my husband who sees through it all.
I have a similar situation with my sister. She presents as a wonderful church-going woman, to her church friends. It was hard for me to understand how she could be so awful to me. What I came to understand is that people with BPD (pwBPD) tend to hold in their bad emotions and dump them where they feel safe, usually with family.
Another unpleasant issues is that pwBPD tend to do a smear campaign on others. My sister has done that with her church friends.  :)uring her last rage event, before I went NC, she told me that her church friends tell her that I'm jealous of her.
Reading about
FOG (Fear, Obligation and Guilt) could be helpful for you.
I have responded to her if she gets in touch but don't bother contacting her otherwise. Has anyone else had a similar struggle with close family? I feel sorry for her at times but know deep down she won't accept any responsibility if I tell her so I'm stuck with feeling guilt, anger, upset and drained if I go back to being 'normal' with her but can't cut her out completely. Please help!
I can relate. My sister really went off the rails when both our parent's health began to fail, and we lost both of them within a 6-month period. My sister
SPLIT me black when we first were forced to work together in regard to our parents and various situations. The first hint that something was radically wrong, was when we started to discuss helping our elderly parents acquire some assistance devices for their home.
In earlier years, I had limited contact with my sister. She went through a horrible divorce and there was always drama. We always had contact during family gatherings (and prep for gatherings). Other than that, we had a couple face-to-face contact during the year and occasionally a phone call between family events. Until now, I didn't think about going into a limited contact situation, it just evolved from my instincts to avoid conflict.
Some people change their level of contact with the BPD in their life. Just because you choose to go no contact (NC) for a period of time, doesn't mean it has to be permanent. You can fluctuate between NC and LC, as needed.
You can't change your sister. You can only change yourself. By using some specific skills and changing the way you interact with your sister and react to her, you can make things better for you. If you go to the large green band at the top of the page, you will see a "Tools" menu. That can be a good place to start with some of the lessons. You will find that boundaries and validation can be useful tools.
Some people like to practice some of the skills and get feedback on how to apply them to their specific situation. Check out some of the tools and let us know what you think.