It is a bit of an eye opener when we first realize there is a name for what has been going on, we have all been there.
Here is a good place to start the process of getting your head around it. The folks here really understand, you probably feel quite alone and isolated at the moment.
You both have your parts to play in this, and to an extent your recovery paths will be independent. The odds are you have a degree of enmeshment and codependency issues, being in a BPD relationship creates this.
Your first task is to relearn how to be an independent you, this removes a lot of the toxic reactiveness that is most likely happening.
First step is to stop making things worse. This will give you the breather your require
Lots of good info for you
here