I always find myself being cast as the role of a bottom in hookups and relationships.
LW: Perhaps you've heard the expression: "No matter where you go, there you are." I suspect that you approach all your encounters with a self-fulfilling expectation of bottoming, and you may be transmitting that message unconsciously.
May I suggest that the next time you want to top, you think of it as a role-playing exercise. Put on your, uh, "top hat" and become that assertive, dominating, possibly assholish guy that you don't allow yourself to be in normal life.