Sometimes it helps to see how other people break up in a sane way. The other night I watched "Becoming Warren Buffett." He and his wife raised his kids and had a lovely, typical Brady Bunch life in Omaha.
Then, once the kids were older, his wife decided she needed a life of her own. She still loved Warren, but she had to fulfill herself in a way that didn't include being Warren's SO, living in Nebraska. So she moved to San Francisco (ironically, I was in a hotel in SF at that moment).
Of course he was a relatively healthy guy, so they were able to maintain a friendly relationship, and she asked her friend to look in on him because she knew it would be hard for him at first.
But he survived, she survived, they all survived. And she simply made her own life happen. No apologies. That was inspirational to me.