heres the thing.
there really is no such thing as "bpd episodes".
bpd is a set of maladaptive personality traits that are, by and large, engrained. the fear of abandonment and engulfment are not episodic. personality traits are not episodic. what you are seeing is a growing manifestation of the difficult person that you love.
thats not to get all gloom and doom on you

. i think one of the hardest things about loving someone with bpd is separating the person from the illness. our loved ones are not defined by bpd, and it would be a critical mistake to attribute everything they do, say, or think, to bpd. on the other hand, they are not bpd one moment, and not, the next.
a lot of what you are describing, and, in the sense that it feels and seems episodic, is emotional dysregulation. it is true that there are a variety of factors that may set your partner off (especially stress), and they may wax and wane, but this is a feature of BPD. if you bend over backwards trying to predict or avoid the next one, youll find yourself walking on eggshells. you may, on some level, already be heading down that path.
none of this is to say that there isnt hope. in my time here, ive seen everything from dramatic improvement, to "just enough", to getting in a healthier place to make a difficult but healthy decision, to really awful scenarios. everything really depends on the connection the two of you have, and whether you are prepared to emotionally lead an emotionally challenging relationship. things can improve, but only when we accept things at face value and are realistic about them.
you also describe loving a jealous and needy partner who feels slighted when your time and attention isnt focused on her, and/or is focused on someone else. this is among the most common issues here. it was certainly fare in my own relationship. whats important to understand is that you cannot reassure her out of this. there arent magic words to make someone feel a different way. but there are a variety of ways to deal with it in a constructive matter, that, importantly, build a foundation of trust in ones relationship, that is able to weather the storms, even though there will be storms.