Welcome to the boards, overperciever!
You are definitely not alone in this.
Our parents' opinion has more power in our lives than we would like to admit. And that is true even when we are adults. If they aren't healthy, their words can be really painful... .
He apologized the next day, a few hours before I dropped him off at the airport to go back home. However, I am having a really hard time letting his words go.
Is there anybody else who has had a BPD father say things such as this to them that they have a hard time letting go of? Any coping suggestions? I don't want to dwell on it, but I'm having a hard time.
At least your father apologized - that shows that he has good intentions in spite of his illness... .
As far as letting go of his words and them not affecting you in a bad way: what have you tried in the past? Have you tried therapy? Having a hard time is normal - it takes time to work through the issues of our family of origin (FOO)... .