Any advice for accepting the facts?
Hello and welcome to the forums- I'm so sorry you're in this situation and I can relate to how heartbreaking it can be. For me, it was the same ending after a 24 year marriage...it ended out of the blue after a few overlooked signs the weeks before.
How do you accept the facts? It would honestly depend on which facts you're talking about and I am sorry to say that as you process through this, there will be more questions than answers.
The most valuable truth for you to accept at this point is that BPD is a mental illness that makes it difficult to keep close relationships. Your partner felt insecure in the relationship (maybe for the first time) and had some doubts, and because BPD's are so geared to run off of emotions (instead of logic), those fears intensified. The time apart may have served as a catalyst for her to become hyper-focused on the "problems" and drove her to a disordered solution- the relationship is over, break up with him before he can hurt you any deeper.
In other words, she broke up with you out of self-preservation because she was afraid you were going to abandon her.
Now, that might not make things any easier because it doesn't make any sense. After all, it wasn't your plan to abandon her in the first place. That's the mental illness though and BPD causes disordered thinking. The closer you are to someone, the more powerful the fear of abandonment becomes.
The second truth that you must accept as quickly as possible is that this wasn't your fault. It was impossible to see this coming and you didn't do anything wrong- you simply expressed that you had a bad day and needed some "me-time". That's perfectly normal in a normal relationship since we all need that. There's no way you could have known how this would play out. So forgive yourself...this wasn't on you!
One more truth, we're up to #3 now. You'll be replaying conversations in your head trying to find your fault (it's not your fault!) or discover things that you should have done differently. Maybe she reaches out soon as well and expresses a variety of things. This is disordered thinking on her part that's driven purely by emotions in that moment...and it can change very rapidly. One minute she still loves you, the next minute she never loved you. Those statements are all true in that instant in time.
If she's hurt, she lashes out. If she's lonely, she expresses love (or lust). If she's sad, she looks for a shoulder to cry on as the victim. You'll wonder what's the truth- how does she really feel? It's all true in a disordered thinking kind of way. A lot of what she says while being in a disordered state won't be remembered 10 minutes later, that's just how it goes. So don't take what she says personally and remember the first two truths. She's sick and this is ultimately not on you.
It's heartbreaking for sure, and I wish you all the luck in the world as you process this. Please continue to ask questions as new realizations come to mind. This is absolutely a process of grieving and yo must go through this to heal, and know that there are no timelines here. I hope that helps!