Think about when your mind doesn't stop. Is it connected to some other anxiety producing activity? I find that just walking out the door to a noisy world with cars whizzing by and a picture of activity overload, or being in a more stressful situation, does it to me. I have major problems falling asleep, made a lot less by using strategies that help me. What will help you is something you have to try… and keep trying different things until something resonates with you.
Yoga, meditation, having a special quiet place (even if it's just in your mind), doing things you really enjoy, things that engage you and make you lose track of time, exercise, even some herbal teas (yuk for me). All of these can be calming and have lasting effects.
Anxiety is a fact of life for most of us, but there are certainly steps you can take to calmness, tranquility and peace. Not saying it'll totally go away, but if you could minimise it, wouldn't you want to try?
Guided meditations are better because you have to concentrate on the speaker. Mantras are good because you have to concentrate. I like listening to Deva Premal - it's very calming for me. Yoga to a DVD at home is better because you're not worrying about what anyone else in a class thinks (which is unimportant anyway), or getting to and from that class.
I'm used to going out with earphones in my ears and really dark sunglasses (done it for many years), and to meditate, all of which helps with coping in a world that wasn't made for me, but in which I have to function.
And I'd be doing these things regularly, not just when you feel "it won't stop". It trains the mind to be calm, even when you are ok. Set aside a time each day to do what works for you. It might be a bit of a journey to find that thing that works, but it's definitely worth it.
_________________
Your Aspie score: 130 of 200
Your NT score: 103 of 200
HSP: 27 of 27
BAPT: You scored 90 aloof, 107 rigid and 63 pragmatic