Has anyone had a similar experience? How did you overcome your partner's fear of hurting you in the future?
Hello and welcome to the family. We have all experienced what you're going through now and it's fairly common with a BPD partner. Many relationships fall apart over this exact problem- the BPD person fears they're going to let the partner down or make their life harder, so they focus on everything negative until they convince themselves that you're going to leave. So what do they do? They leave before you can hurt them by leaving.
It sounds counter-intuititive, but that's literally all of our stories here, the beginning of the end. Things are great, then they're awkward for a few weeks, then they run.
Now, I'm now saying that your relationship is ending. Instead, I'm pointing out how important this exact topic is in BPD relationships because it will become more intense over time, particularly when your partner is under a decent bit of stress. It could be around the holidays, or the week a family member passed, or just a tough stretch at work or whatever. How you deal with this will set the tone on how the relationship progresses.
To answer your specific question about overcoming this, it's about positive reinforcement, validating their feelings, and letting them know how much they mean to you. So tell them how you feel often, especially when things are a little tense. I love you and I'm not going anywhere. It's okay, we can work through this together.
The other side of that, the validation part, you know what it feels like to be scared or rejected. So empathize with that and let her know that you understand. This helps her thought patterns "level out" and keeps things from getting worse. Tell her that you want to talk about it, you want to be there and to help her. And let her know that you feel like that sometimes as well, that you don't have it all together 100% of the time.
I hope that helps!