Dealing with BPD can be overwhelming and we can struggle to find our role to play
Do you still have a belief that you can "fix" him, or are you more focused on protecting yourself from the consequence of this disorder.
Does your inability to fix him in itself cause you self doubt? It is outside your scope of expertise to fix him, this is something you will need to accept. Your goal is to create a safer environment rather than try to force a "normal" one
OCPD will tend to cause you to micromanage him, hence down the path to enabling. OCD would more likely paralyze you with anxiety
Start by working through the Lessons on the right. Particularly the section
Understanding your role in the relationship