don't be so hard on yourself. you at least had the courage to do what is in your heart and leave your dojo. not an easy thing to do. i am planning on moving geographically, and when i do, it will not be easy for me to leave my fellow Aikidoka.
in my opinion, you are experiencing a shift in focus, and it will take some time to adjust. i don't think it has anything to do with whatever martial art you're studying; you're choosing a different direction, and you can't expect to change with the snap of a finger.
kind of an open ended question: how relevant is power in other martial arts? do you have to be stronger than someone to defend yourself?