Can/will she get better? Can/will I? Is salvation possible? What will it take?
all of these things are possible, absolutely.
whether they will happen very much depend on you, and on her.
When researching how to recover from betrayal trauma, all the advice says I need to grieve, have honest discussions with her, and establish boundaries. Anytime the affair is brought up, however, she spirals. I can't heal because she is unable to confront her actions without splitting and panic attacks. I've gotten responses like, "It's been 6 months already, I'll never be good enough for you."
recovering from infidelity is extraordinarily difficult as it is.
it is not uncommon for either party to struggle - either for the guilty party to really hold themselves to account and work to repair the damage in a way that feels adequate - or for the damaged party to heal, trust, forgive.
but with bpd, you have some added layers. one of them is shame. people with bpd spend a lot of their lives both feeling, and running from shame. it colors so much.
a lot of what youre seeing is over-compensating for the shame she both feels, and cant allow herself to feel.
when it comes to trying to heal and recover from this, its really important to have realistic expectations, both in terms of what shes capable of being accountable to/for, and yourself, in terms of love and trust.
in essence, your wife does not have adult coping skills. affairs and suicide threats are coping mechanisms. they speak for themselves.
and in general, people that have hit rock bottom in life dont have them either. think of it this way: people dont enter rehab on the straight and narrow, with their

together.
so, all that is to say, your wife is probably not very capable, right now, of validating your pain. she is likely not very capable of confronting her actions, or being confronted with them, without spiraling into shame. shes probably not very capable of being accountable to the degree you feel you need to see. and unfortunately, thats often the case with most people in her position.
what is very promising here, is that she sought help. that is one major demonstration in it all, the admission that she has a problem, and the willingness to seek help. but she wont get there, wont "be helped", over night.
this was written for parents, but is very applicable here:
https://bpdfamily.com/content/support-child-therapyAs a result, I'm choosing to absorb the pain of it all.
it would be a very good idea for you to seek a therapist or counselor of your own, as part of your support system. someone who, in addition to us, can be a sounding board for your pain, and helping you navigate it.
there
is real hope here. the best thing you can do right now, for you and your family, is shore up your own support system, and that would be true whether your wife was more ready/capable to be accountable or not.