My OH went through a phase of being absolutely terrified by turbulence. She did the BA course, thought it was fantastic, then all that went out the window when the next flight got bumpy. That's what panic will do to you... all rational thought disappears...

All I can say to the OP is that turbulence at altitude has never caused a plane to crash. And turbulence that causes injury is rare enough that it is news - if it was frequent it would stop being "news".

And on a popular flight path such as JFK-LHR, pilots communicate with one another to help each other avoid turbulence. Even if it is unavoidable, the "fasten seatbelts" sign is turned out well in advance of any potential issues.

But ultimately, "phobias" such as this can only be treated by qualified psychologists, not frequent flyers on an online forum.