I'm quite similar to this dynamic but the way I explain it to my husband is "I often don't know what I think until I try to communicate, so when I overexplain it's because I'm trying to understand why I felt the way I did, I appreciate you providing a safe space for me to do this, and I love you so much".

And then he's totally supportive of working this through with me. And we do work things out and feel closer as a result.

I try not to use blaming statements, more "I feel" statements. And it usually results in me figuring out why I was triggered and what in my past affected me.