Look Up Some Diagrams
A steady state fusion reactor for power and a fusion rocket are not the same thing. You are also way off on fusion's future period. It wasn't easy to figure out how to fly either despite centuries of effort. We've only been after fusion for less than a century. The retarded international cooperation approach is as much to fault for lack of progress as technological barriers. Multiple trials amongst countries striving for economic dominance provides a much stronger driving force than can't we all sing cumbyah together.
Regards,
Mark