Your story is very much like mine. My wife and I have had 2 miscarriages and like you described, she remembers all the details and I avoided it. She felt alone when she needed me because I was trying to be strong for us. There really wasn't any way forward for us.
Then I just broke. We lost our child almost 10 years ago, and adoption came up recently, and I couldn't. I broke down and finally shared the pain of my loss. In that moment we finally came together over the loss. My wife didn't need someone "to be strong" for her. She needed someone who shared her grief. Someone who not only understood, but whose reaction validated her own. We both needed someone to talk to and by not sharing I was only as useful as some average friend who doesn't know what to say and so offers polite sympathies.
I spent so much of my young life being told to be tough and that boys don't cry that I stuffed it down for years. But I'm old enough now to have learned that being tough doesn't impress anyone. It only makes you useless when the woman you love needs an emotional bond.
That's my experience anyway. I hope I said something useful.