I just went through this and it killed me. Absolutely destroyed me. The waiting for the inevitable is absolutely agonizing and I ended up hospitalized after it ended.

Surround yourself with supportive people, like friends and family with whom you can spend time. When it ends, you'll be in a lot of pain. Somehow, the pain of it ending was less than the anticipation of it, at least for me. It's absolutely horrible, don't get me wrong, but there was at least a bit of relief in the anxiety. But when it is over, cut ties completely. Don't crawl back and try to "fix things" because they usually don't work out. I've learned that the loss doesn't change the behavior or the anxieties that we as BPDers possess. It doesn't make us learn the lesson and magically we're be different - or at least it didn't for me. For example, recovery from addiction is often spurred by loss, but it isn't the loss that fixes us - it's the push to get into recovery because of that loss that can fix us.

Don't take my words as gospel, as I'm still in pain from my own loss, but just know that these things I've written are what I wished I had been able to do. Too often I wandered back to their Instagram and Facebook and caused myself unnecessary pain when I should have moved on. And had I not already cut out everyone else after this loss, then perhaps I would have been able to surround myself with supportive people who cared about me, which would have helped me so much. I'm sure you know this, but recognize that you will be hurt and the pain will be hard to bear. But those of us with BPD are quite often literal survivors who can and have weathered so many storms.

Good luck.