Hello Thryoid Warrior,
I'm also a Thyroid Warrior! There are a few of us here and you'll find a thread in "Other Health Discussion" called "Thryoid issues & support".
I'm right with you on the driving anxiety... I haven't found a "cure" but chewing gum, singing out loud, opening window, keeping the mind busy helps. If you could get a hypnotherapy session beforehand it could really help.
Also, Petit Grain essential oil is great for anxiety. I just recommended it to someone else on a different thread. Will go and copy/paste...
You take 2 drops 3 x day on a neutral support (small piece of bread or spoonful of honey) and you can also rub 2 drops 3 x day on your solar plexus, wrists (and inhaaaaaaaale) and instep. It smells quite strong, that's the downside but it's like nature's Xanax. I always have it in my bag (bit of a nervous person since Hashimoto's kicked in).
All the best.