Hi Braves918, welcome to the group
Yes, pwBPD can struggle with "all or nothing" thinking, where even an honest mistake can become "the unforgivable event". So difficult to cope with, and you're left reeling.
Can I ask, does your friend have an official diagnosis? Or is this more "putting some pieces together" on your part?
Occasionally giving the pwBPD space and time to self-soothe and come back to baseline can help make things less bad. Has that happened over the last few days?
Fill us in whenever works best for you;
kells76