The next time you fly be sure to stop in with the flight attendant greeting you at the door. Let them know that you are a fearful flyer and are already pretty nervous about this flight. Once I know I have a nervous Nellie onboard I check with them often (I'm a FA) to be sure all is okay. Talk to your seat mate and make a friend so in case you experience that turbulence they will know why you are grabbing their arm!