I know that you're scared, we all are. If there is anyway you can try and focus on other things, more positive things, you should. My boyfriend is in the Army and everyday I'm scared he's going to call me and tell me he's being deployed. I would have gone bonkers by now if I let it get to me. I can't control it, so I'm not going to to torture myself by playing 'what if'.
I have faith in my government, I have to. Where else am I going to put it? Besides God, and I'm not downplaying that, just saying that this is in the hands of the people that we elected to lead us, through good times and bad. All I, or anyone else can do is try to live as normal of a life as possible, try to be more observant of our surroundings, more loving with our family, show more kindness to strangers, and appreciate this wonderful country that we have.
I just feel so sorry for you because you're freaking out, and things are only going to get bumpier. Don't do this to yourself. Don't let the terrorists win. Try to find the joy in the small things.