Welcome to the world of anxiety. Sounds fairly classic to me.
One thing I can recommend is find out if your bc's have these symptoms as one of their warnings. Ask you doctor or pharmasist about it. If this is one of them, talk to them to see if there is another one that might be better for you.
Controling them is another thing. I find that what works for me is to avoid situations where these feelings can come in and "grow" in your mind. I find this happening when I am doing something that doesn't take any brain power. My mind becomes vulnerable to these feelings and thoughts.
My remedy is to drop doing this no thought thing and immediately start thinking about things that require my attention and thought process. If it is not too late, it usually works. Sometimes, it does fill me and I really have to struggle to get control.
But, in the long run, I have learned to fight back. Too many times I have allowed these attacks get control, and I really feel like it is "check out time." not good for you or anyone else around you.
Hope this helps.