Well so take advantage of your garlic eating and start adding cilantro bit by bit till you get yourself up to at least a full 1/2 cup+ serving (minced) per day.

Doesn't sound like you have severe poisoning, maybe just a tad. If it were severe you would have problems walking and you be numb all over, trust me, I've been there.

But chelating will keep it it from getting worse till you can get the amalgams removed, and from my experience cilantro is the best for a happy head.

Basil should do wonderfully in GB or just about anywhere except the Sahara or Antartica for that matter. It loves rain, it doesn't mind dry, loves sun can handle a lot of cloudy... it's a short season, ready to eat in 6-7 weeks. Grows under any conditions really except freezing from my experience, I've grown it for several years in both drought and rainy seasons. Cilantro about the same btw, very short season is the reason why. They'll be short and stocky in dry weather, tall and lanky in cool rainy weather but they will grow either way.