How do you let go of harsh things said to you by someone close to you who you love?

I had some very harsh things said to me by someone in the past (they were very frustrated with me and in one instance very drunk) they have not said those things again and they regret them. When they are angry with me now I find myself 'triggered' and feel like I am taken back to where I was back then. I fear that they will say those things again to me, and this is how they really feel about me.

I have periods where I think I've processed this but then anger = trigger and I feel it again.