Accept it and render it powerless. Thats the only way it wil go away, unless it's a true disorder it might be harder but for general anxiety and panic attacks the best thing to do is know that it can never hurt you and that the more you give it attention the worse it gets.

For herbs try St johns wort, Valerian, and chamomile(tea). They all good for anxiety and have no side effects like the synthetic drugs. Valerian is basicly a natural valium. I find chamomile to be pretty good for nervousness.

I have a huge problem with anxiety towards weed, and thats how my anxiety started. Was just smoking one hit or so every now and then to help with things and got to to high a few times and panicked real bad. ever since I have had bad anxiety towards weed and even worry about it being in food and stuff sometimes. I loved it but now my mind is completely rewired to fear it. I think hypnosis/nlp would help.