Hi and welcome to the family

I am sorry about what brought you here but I am glad you found us. This site offers a lot of information on BPD and many tools for us to better handle the difficult situations and feelings we encounter with our partners. I would encourage you to look around the boards, read through everything that resonates with you and share your experiences with other members. We understand your pain and try to help and support each other as good as we can.
It's common for pwBPD (people with BPD) to isolate their partners from friends and family out of jealousy or fear of abandonment. But if we want to be a positive influence in their lives, we need to be strong and emotionally stable and a support system is essential for that. If we don't protect and care for ourseves, we will be in no condition to support our partners. So no, you are not wrong for wanting to keep your friends, it's great that you have people in your life that care about you and now you have us as well. You need all the support you can get, not only for yourself but also for your relationship. Your girlfriend might not be able to see it that way (yet), but it's a win-win situation for both of you.
How do you think your gf would react if you put it that way?
On the topic of handeling her meltdowns, you might want to look into tools like
JADE,
empathetic listening and
validation. It's easy to fall into a pattern of justifying, arguing, defending and explaining when our partner is upset. This is likely to fuel the conflict. If we want to deescalate, we need to understand where the rage is coming from by listening and identifying the underlying emotions like fear of abandonment or rejection or insecurity. Validation is about accepting these feelings, understanding them and nurturing them. Even if we don't agree with what somebody is saying or doing, we can still try to respond in a way that is validating.
This is probably a lot to take in right now, but I hope it will give you some hope and clarity.
Feel free to share your opinion on the articles or ask any questions and keep posting!