online gf blocked me because of bpd
She didn't block you because of BPD; she blocked you because of how she felt in response to your behaviour. Regardless of how this situation played out or how any specific situation plays out (be it in the past or in the future), the presence of a general deferral of responsibility as alluded to in the topic title would contribute to a toxic vibe in the whole of any relationship.
This, you can work towards improving upon.
But first, I think you'd be well-advised to remove any and all reminders of this person from your life. Leave
no trace of her in your life. Nothing. If you're still attached to her even a year removed from last contact, then this, I think, is the only path forward here. Anything else, you're just tormenting yourself.
You met a girlfriend online before. You can do it again. Eliminate all reminders of your ex and focus on other aspects of your life, including meeting new people.
In the meantime, about this
"...because of BPD" mindset: Obviously, borderline personality disorder manifests itself in ways that, left unchecked, can have a detrimental effect on relationships. But part of managing this involves owning your own behaviour and accounting for your wrongdoings by apologizing (sans excuses), acknowledging responsibility, offering to make amends, stating what you'll do differently in the future, and then following through on that commitment with meaningful effort to do better.
Improve upon this mindset, keep learning and practicing coping mechanisms for managing BPD in general, take steps to meet new people, and something better will soon follow. There is no question that you do have this in you -- somewhere.