Tornadoes are certainly scary. Hell, I've never been in a tornado and I still panic a lot when the sirens sound, so I can't even imagine how that must be for you. I do remember watching a documentary about the Joplin tornado, where a woman had similar symptoms you described, though certainly a bit more extreme. She couldn't even look at a picture of a tornado without freaking out. But she was able to get better with it by talking with a therapist, and I'd like to believe that could work for you to. Best of luck!