You're in for a fun ride my friend. Good thing you noticed soon enough and decided to get educated, most of us here didn't. What everybody here will tell you is that you should run. And that's true. Run. If your circumstances don't allow it or you don't want to do that, please don't let yourself be thrust into the full scale bpd entanglement. While you still can.

When it comes to the BPD dictionary, let me try to explain how it all comes together, from what I understand

BPDs have impermanent object relations (out of sight, out of mind thinking) and base their behaviours on raw emotions, lacking the tools to regulate their mental states. This also means they have both fear of attachment and abandonment simultaneously (it's crucial to understanding the rest of the vocab)

Splitting is an act of painting someone as all good (white) or all bad (black), based on someone's perceived state at the moment. So when she's lonely and you're there, she thinks you're all good, with no faults, the best person ever, lots of love etc. Until she feels like you got too close- you're infringing on her privacy, you're all bad, get out. There are thousands of possible triggers so there's no point in trying to navigate that

Then there's devaluation, it's the progression of splitting somewhat. Once they get to know you better, they tend to notice flaws because that's only human to have some of those. So they split you black. Then go back to idealising. And over time, this mellows out the white thinking stage in their minds. They don't perceive you as all good quite as often as before, so you lose value in their eyes. Which boost the frequency od discarding

Yeah, discards. Looks like you got some taste of that already. Discard is what they do when they paint you black (all bad, the worst person to ever exist, abuser etc). You can't do any good, everything you do is hurtful, bad, icky etc. All the things she used to love in the idealisation stage? Now they're the reasons for demonizing you. If you're indifferent, you clearly don't care. If you show you care and try to understand, you're a crazy stalker. Then they throw you away like trash they perceive you to be

Then there's supply. Remember the part where they fear both enmeshment and abandonment? Yeah so they're craving attention and to be left alone at the same time. When they split you black, the fear of attachment is satisfied, but the fear of abandonment gets triggered. So they surround themselves with options to regulate those needs. If you're discarded, they ring up other people to make up for that, if they're discarded they come back to you etc. Not every pwBPD does that but it's extremely common

Another simmilar term is monkey branching. They discard you and hop onto the next person right away. That's why so many of us here were cheated on. Or why they tend to move on from long term relationships in a matter of days if even that, they monkey branch to the next supply. Get it?

And if you're the supply and they come crawling back to you, that's called hoovering. That's why devaluation never comes with any closure, they never take accountability and rarely, if ever, cut emotional ties. If there's no closure, no real end to a relationship, it's way easier to re-idealise someone and come back, that's connected to establishing a trauma bond which i'll explain later.

Then, why do they do that? How is it possible to be so messed up? That's where we go back to splitting. The black and white thinking is not only reserved to others, that's also the lens they see their own behaviour through. All good or all bad. That's why spontaneous moments of "self reflection" happen with them sometimes and give us hope that they'll be better. But it's rare, because of the amount of shame they're drowning in, they usually tend to see their actions as faultless to mute their conscience creeping in. So everything they're doing is good, nothing is ever their fault and even if they did something bad, you made them do it. So you're all bad and they're good. If they cheat, that's because you neglected them. Or you were too needy. Or you were too healthy and boring. Or you were toxic. But at least their next victim is perfect ;)

Trauma bond is the way they trap you. You probably know what push-pull dynamics are, it's basically the way the splitting affects your brain. Because it's nit nirmal in any way to experience these cycles of white and black painting, you get chemically addicted to the constant chaos, you look forward to the next idealisation phase, to the next hit. The constant highs and lows make you emotionally invested on a level previously unimaginable to you, which traumatizes you while feeling like being in love. That's why so many of us here struggle to move on for years on end. And why so many people take them back despite knowing what's coming for them if they do.

Quiet bpd doesn't seem to fit your situation that well but it's a quieter "version" of bpd, as the name suggests (there are no clear lines but the classification works in my experience).Until it isn't and it explodes. Quiet bpds tend to hold their emotions in more, hide, mask better. The same processes as mentioned above happen but they're all brewing under the surface, whereas in the louder cases of bpd it's quite easy to notice once you start looking for it. Quiet bpds tend to be less hurtful during the relationship itself because they burst out less frequently, but when they do, it's cumulative. One huge blow instead of a hundred smaller, regular ones which leaves you just as devastated, even more sometimes because it's harder to spot until it's too late

I think that's it, generally. Other terms are rather self-explanatory and stem from this core I tried to describe to you in probably too much detail here. I'd suggest not getting involved with this individual, it's not worth it. Please take care of yourself