Im sorry you are going thru this. I know how hard it is, I have very similar issues. It was much worse years ago and I went to talk to a counselor about it, and found that it was all related to things going on in my life at the time - I was in a bad marriage and felt trapped. That spread to other areas of my life, so while driving on the highway I felt trapped (with no shoulder or exit) same with being in big crowds. At least this is how the counselor explained it. I am much better now but still have issues with driving on the highway, and I don't really know how to overcome it completely.
So maybe you should try talking to someone to figure out what is causing the anxiety? A lot of companies have a free counseling service that is confidential as a benefit to their employees, maybe your's does? I was also really against taking drugs for it and I have never tried. But, if you are really having a hard time I don't think it is horrible to take something, as long as you make an effort to work out the problems thru counseling at the same time, then you can wean off the drugs.
As for a natural remedy, I don't really know of any quick fix, but the main thing to help while you are having an episode is distraction, if you can get your mind to focus on something else, like do times tables in your head or something. I know it's not that easy to do. Also, here are the other things that helped me:
Exercise - because it releases a chemical in the brain to fight depression & anxiety
Muscle relaxing exercise (you have to do it every day):
How to Perform Progressive Muscle Relaxation - wikiHow
Yoga has helped me a lot, if you can take a class it is much better than doing a dvd of it at home.
I also had some cd's that the counselor gave me that really helped, I can search for them and tell you what they are called, I know you can get them off amazon. They are like guided meditation type of thing, but its hard to explain.
I hope this helps a little, I know this is a really hard thing to go thru. feel free to PM me if you want to talk more