Amethyst Question

Hello! I came across your page while looking for some information regarding the metaphysical properties of amethyst on your website, and I had a question. Sometimes when I'm stressed out, anxious, or fearful, I put on my amethyst necklace. I've noticed that my anxiety, etc. is usually relieved in a matter of minutes, but I've also noticed that if I wear the amethyst necklace for a longer period of time, I get high strung and jittery, as well as feeling like I'm not fully grounded. Could it be that I am experiencing an amethyst overload, or do I just need to have a grounding stone with me when I wear my amethyst necklace? Also, the necklace that I have is made up of little chips of amethyst, and it's quite a long necklace (it comes down to around my solar plexus), so I don't know if the "overload" I'm experiencing is because there's a lot of amethyst chips. Do you think if I wore a smaller amethyst (like my amethyst merkaba, which is smaller than a penny), I wouldn't feel the overload so much? I've also noticed on occasion, that amethyst makes me sleepy (altho not at the same time that I feel the overload.)

Do you know if the things I am experiencing are typical of people who wear amethyst?

Thank you very much for your help. I greatly enjoy your website.

Have a blessed day!

-Stefany C

P.S. What stone would you recommend in helping me to overcome my fear of thunderstorms?