Intimacy and Autonomy

I'm trying to find the middle. What is the midpoint between caring and self-sacrifice? What is loving and what is subjugation? How do I take care of him and not lose me? How do I learn about his life and not lose my own? This is the challenge in all relationships—the balance between or the pendulum swinging from intimacy to autonomy. A good relationship needs both for both partners. But it’s never at the same time. I feel vulnerable here, like I could get lost, drown in his life, lose my own. And then what? Hate him and me.