I have never had this much clarity and please tell me it stays and it's not going to be a fleeting moment like when BPD's regulated happy moments.
I've been working on myself with a sponsor in Al Anon for nearly two years.  (In addition to BPD there are addiction issues in my family.)  I've changed a lot of things about myself.  I'm better at setting boundaries and detaching from my BPDw's emotional dysregulation.  However, I still make lots of mistakes.  Sometimes, I have a lot of clarity about boundaries I need to take care of myself.  Sometimes, things get foggy and I get enmeshed.  There's a slogan in Al Anon, "Progress, not perfection."  One day I hold a boundary and celebrate a victory.  The next day I capitulate on something important, remind myself that I'm not prefect, forgive myself, and figure out what I can do better next time. 
I wish I could have a sudden epiphany, a mental switch would flip, and I would find myself an instantly changed person.  I'm 47 years old.  I have a lot of bad habits to work on.  The changes are gradual.  However, when I look at where I was a couple years ago versus where I am now, I know I have undergone some amazing and profound positive changes.
If you have a bad day, your light bulb goes dim, the clarity isn't there, and you find yourself falling back into some bad co-dependent habits, don't beat yourself up.  It just means that you had a little slip.  Stand up, brush yourself off, and get moving again.  You can find the clarity again.