Unfortunately, no tornado shelter. The park where I live now is in quite a different situation in many ways than where we lived before. One of the big helps for me with my fear is knowing that, while the place where did live did not have adequate tie-downs for the trailer, the one where we are now is more than adequately anchored. While I have not been able to renew any formal therapy since the tornado, I have been working to deal with the effects as best I know how. Unfortunately, when one's health insurance doesn't cover such things, it makes it quite impossible on a small budget.
I really like your description of how you deal and manage to try to figure out the differences. It is somewhat akin to what I do to calm down, but I haven't made it completely through the next step yet. Generally, if I have something physical that is causing anxiety, I check my two biggest fears; I check my pulse to make sure it's not erratic, and I check my sensitivity to touch by biting my tongue or lip (since my first fears are heart attack or stroke; my symptoms often mimic the feeling of these problems). Once I've reassured myself that, yes, I'm not dying (lol), I try to calm down with meditation or breathing exercises, whichever seems to be working better at that moment. Since I can't always feel myself breathing in these situations, sometimes the mechanics of breathing can be more anxiety-inducing, so meditation is often the way for me to go. But as for getting others to help, this is usually not something I can do, because the "events" are almost always partially triggered by being alone.

Which is part of the reason I know that some of the root causes are PTSD, even when I'm having SPD issues.
I suppose I am asking myself to do the impossible; I am trying to take care of large amounts of anxiety and SPD problems without the help of professionals. But, since I am now without even basic medical insurance (as of last week...

), I have to figure out something. It doesn't help that there are also plenty of other problems going on that only exacerbate these things. But such is the hand I am dealt at the moment, and I have to figure something out. It helps me a good deal to hear how you are coping.