Ditto to what Maya et al have said. He’s scared, Slowly. Scared to trigger that unhappy period in your mind, scared to confront his own guilt through your eyes once again. I think what Maya suggested might actually make it safe for him to share this. And I’d do it on a day and hour when YOU are feeling really secure about the relationship. That’ll transmit to his little antennas.
Hang in there. You’ve gotten soooo good at this I’m continually in awe.