As I read, I felt repulsed by you. On one hand, you are brutally honest about your actions and I can appreciate that. On the other, you are not as honest with yourself. And certainly not the kind of man I'd ever want as a partner in life.
My stepfather cared for his dying mother (cancer), and his dying sister (cancer). Then he raised his nephew as his own after his sister died. He was in his 20's when all of that happened. He was young, handsome, and fit. He could've abandoned them all for a "great" life. Instead, he sacrificed for his family. Now in his 60's, he is surrounded by such a strong, supportive group of people. Everyone in his life is quality, because birds of a feather flock together. He's there for people and they are there for him. He's built a network just by being a trustworthy, empathetic, and kind human.
You deserved to have a life, and the feelings you expressed are very real, but your reaction was selfishly executed. I'm not surprised to read you are living in solitude when you only fostered a life for one person: you. It was heartbreaking to read how you described your wife: "hung onto me like a toddler while I packed my clothes." You, sir, are the toddler. You are the one who needed therapy. You still do. You said the worst thing you did was not leave in the early years. I'd say the worst thing you did was make all your unhappiness your wife's fault. I wonder how much your daughters will sacrifice for you as you slip into old age?