If possible, if you can, taking a break and trying to immerse yourself in things you enjoy, or at least that can take your mind off of it, and allow some distance from the hurtful behavior can help. Reminding yourself it's not really YOU, but a condition they can't always control causing it.
Hi feelingalone12,
I second what
isilme said. And also remember the good in him. Tell yourself that BPD is a part of him, is not his whole being. One thing that helps me a lot is not to dwell on what he says (and it's really hard not to, but I try to do it anyway), because he says a lot of really, really hurtful stuff that I feel ashamed to repeat. I tell myself, it's his way of voicing out his negative feelings, and because he is not emotionally mature enough to process the feelings, he has to resort to using very primitive, childish means to do so.