While we have never gone to Universal Studios before, both of my boys (ages 8 & 9) have "caught a fright" from things they've experienced and it spills over into their daily lives. They have always had a facination with dinosaurs (what child doesn't?) and love the Jurassic Park movies. They have never jumped or screamed during the shows, and while I've had my apprehensions about allowing them to watch the movies, they insist that they are not frightened. But, my youngest son has grown to be afraid of being upstairs alone, or in the dark. While we have done all we can to console him, the fear is ever-present and keeps him from full independence while upstairs in his room or in their bathroom. My oldest son is incredibly afraid of the wind. We had straight-line winds come through here last summer and, while no one was injured, it truly startled him. Now, he locks all the doors and closes the blinds if it advances past a gentle breeze. Again, we can't tell him enough that we will never stop protecting him.
I believe it is something that children commonly experience. While we, as parents, wish they could simply trust our promise to be there for them, we know that fear is frequently stronger than promises. The best thing we can do for them is to allow their emotions to take their course, keeping them calm, and prove to them that we will never purposely allow danger to strike. The best thing for initial fear is distraction... taking their minds off of their anxiety and showing them when the elements have passed that bad things don't always happen when we think they will. For us, prayer is absolutely amazing. Telling God how we feel and asking for His providence always makes it easier to deal with life's situations (whether we are young or old). Christ won't give up on us... let's not give up on Him!
Hang in there, M., and know that you're not alone!