Let's work through this a little bit to see if it helps.
Basically the behaviours have become quite a lot for me and I've become roped into the drama and need to take a step back.
Drama is a hallmark of BPD relationships and it stems from insecurity in the relationship. The closer you get, the more present it will be as her fears escalate.
My friends are saying I deserve better but I know her behaviors stem from trauma.
You're correct and it's good that you can show empathy for her situation, but you also have to realize that your friends have a valid point as well. Her trauma defines how she builds relationships and it is not your fault...it's not a "you thing" to fix.
At the same time I need time to centre myself but she is struggling with even meeting once a week as she is taking that as me abandoning her. So I'm trying to balance giving myself space and not triggering her abandonment issues.
Have you expressed these feelings to her? And if so, what was her response?
With BPD, there's a clear push/pull dynamic where the relationship is always in flux. One of the coined phrases from an author on the subject is, "I hate you...don't leave me!"
A lot of blame is being thrown at me and it's difficult to say anything without it being torn apart. I get that I need to communicate differently but I'm struggling with what that is, everything I say seems to cause her offence and when I ask her to take accountability she acts sarcastically.
If I said to you, "My foot hurts", how would you respond?
Your answer to your girlfriend should be the same as how you'd respond to me. However, with your girlfriend and BPD, maybe she doesn't say 'my foot hurts'...maybe she says 'you never listen to me' instead. The goal is to focus on the emotions she's feeling and respond to that, the source of those emotions. The words are the way she expresses those feelings in the moment and they are often out of context. Rarely will she say what she's actually feeling...so you focus on the emotions behind the words to comfort her and get out of the stress/drama of the moment.
If I give her the space she gets triggered and when we spend the time together and argue she gets triggered so I'm left unsure of what to do. I know it's on me to understand how to navigate these situations but I'm kind of at a loss as to how
You change the dynamic by doing what I said above. Stop arguing over senseless things and get to the bottom of what's really happening. You do that with affirming statements...I'm here for you, I love you, how do we work through this together? That helps reduce the intensity and allows you to talk about what actually matters.
The flip side of that is what we usually do because it feels natural. She's angry or upset and says something hurtful. We defend ourselves and things escalate in her mind, causing that fight or flight response to skyrocket. So more nastiness is said and more responses make the situation even more unstable. Now someone is crying or yelling (or worse), and a small problem turns into a bar room brawl.
All this happens because a person with BPD turns off logic and relies purely on emotion when they feel unstable. So you soothe them, help them stabilize with empathy and compassion, and they relax to the point of being able to have a regular conversation once again. I hope that helps!