It's without doubt my biggest trigger.

I'm still obsessing, almost two years later, over an ex fp (non romantic, best friend) who did this to me consistently over the space of a five year friendship.

He would continually flake on plans at the last minute, more often than not without even having the decency to let me know he wasn't meeting up. I would literally find out simply because he didn't show up. All messages/calls ignored.

It didn't help that it was always because he'd found better friends to hang with. For five years I asked him to hang out at the weekend, he made excuse after excuse and over that five year period, hung out with me once at the weekend.

Every other weekend was dedicated to his better friends.

I'll never let anyone make me feel like a tenth rate nobody ever again, even if it means spending my life alone.

I'm sorry I have no advice other than if someone consistently let's you down cut them out your life immediately. It's not harsh, it's not due to BPD, it's honestly an emotionally healthy thing to do.

Of course, sometimes people have to cancel for whatever reason, but if it's consistent, then they don't care about you, simple as that.