I believe you may be wielding the concept of agency slightly differently to sociologists — by my reading at least — perhaps evidenced most clearly by your question “Else how can I be autonomous?” << to varying extents you are not.
“Agency refers not to the intentions people have in doing things but to their capability of doing those things in the first place.” (Giddens, 1986)
One can say that the greater one’s capabilities of control, the greater one’s agency. But while control is perhaps the desired object, agency does not presume control.
Having control over a social outcome entails quite different dynamics to, say, controlling the light switch in one’s bedroom. The latter is entirely dumb and will never disagree with you. As and when social interaction encompasses disagreement, one person’s “control” may come at the cost of someone else’s. (Perhaps you want the light off but your partner still wants to read.) Quite naturally then, it is impossible for everyone to maintain control.
In complex systems, I would talk in terms of influence rather than control (with the likes of power theory and actor-network theory linking the two). One may be negotiating in a social system in one context where one’s will prevails, and then in another where, despite no difference on one’s own part, one’s will does not. That’s life. That’s relationships (the pathways for organizing). That’s interpersonal data (the medium of organizing). That’s identity (the sense-making capacity of organizing).