Welcome
we're glad you're here.
The rollercoaster is unsettling and destabilizing. I felt so upside down after dealing with my BPD person for years before realizing what was happening. Finding ways to stabilize and develop my core has been the most helpful thing for me. Posting here, counseling, reading books about BPD and family systems, and supportive friends are all ways to establish a firm foundation.
Does your wife have an official diagnosis? How did you find out about BPD?