Hi, first off I don’t know if this is the right place to ask this but here I go, how do I go about dealing with someone who has BPD? I usually don’t post anything but I have been dating this girl for around four months now. She’s wonderful. Every time I see her it feels like the aura of the room just lightens up. Either way, I feel like we are really connecting and clicking really well. I want to be a really good boyfriend to her But I’ve never dealt with anyone who has BPD or more importantly had some who opened up towards me about it. I guess I do have some questions about it.
1. What exactly is “splitting?”
2. How do I be there for her when it’s happening?
3. Is there ways to help prevent her from splitting?
4. What are things that have helped you in this situation?
5. How do I express to her in a healthy manner that what she said wasn’t exactly the nicest?
6. Do I give her space or be with her during her moments?
7. How do I help her over the phone (we live in separate places when college is not in session)?
8.  Any advice?

So far into this relationship I’ve come to learn a lot but I feel ultimately useless when she’s “splitting”. My approach thus far is being by her side and just talking. There’s been crying and I hold her while trying to sooth her. Or there’s other times where she’s “splitting” and has become rather irritable. She sometimes says things that aren’t the nicest,  I don’t hold anything against her while she’s in this state but I express what she said was not nice and explain why, which I believe works. There’s other times where she is very sensitive. This has been a recent one where it seems as though she is very vulnerable. Unfortunately my dialogue towards her (or any of my friends) is we generally give each other light hearted teasing at each others expense, nothing to the point where it’s hurtful or attacking but just light teasing. The other day we were in the midst of one of our casual conversation and she had said a phrase that I expressed I didn’t like. The dialogue went as followed (was on a call using discord):
Me: Oh yeah?
Her: Yeah?
Me: OOOOHHH yeAHHHHH?
Her: YEEEAAAAHH
Me: Ok! (Hangs up with intent to call her back immediately) 
But I was too slow. 
She expressed that it had hurt deeply and felt abandoned. She didn’t really talk to me for the rest of the day. I felt like I had just crushed her entire day and it hurt me deeply that I did that to her. 
 
I’m sorry if this comes off as rather crass or my terminology is poor, I am incredibly ignorant; I’m just trying to be a better boyfriend and need advice. 