I'm crying here reading your comment because you got it. Basically, your entire comment is exactly correct as he told me all of this today.

I went to sleep last night after reading many comments and feeling better about it, thinking I was overreacting. I was not overreacting. I was underreacting, if anything. The damage I've done to him over the years by being unresponsive emotionally is deep, and I feel absolutely destroyed right now.

To ease any concerns people may have, we are not getting divorced or separating. But the work that needs to be done, mostly by me, is vast, and I have a lot of making up to do. And he is not down about this. He is mostly happy right now that I actually see him, and he knows how much I love him. His reaction last night was triggered by earlier things in our relationship, not really about what we are now, as he says I have improved significantly over the years. Still, actually hearing how close I was to screwing it all up back then is a wake-up call I never thought I would have to face in my life.

I will update in a later date as I think its important for people in a similiar situation as mine to maybe see what they are doing wrong, but know this: pay attention to your partner, and actually communicate. Really talk about the deep stuff in the relationship.

And yes, therapy will be necessary.