The thing about kids and behavioral issues (ASD-type behaviors, specifically, I mean) is that not all kids are susceptible. My daughter has none, and I think it's because her physiology is much more similar to my husband. She has a very high toxic load, and I know it was causing her problems, but the manifestations of it were subtle. A lot of things are off in her body--Kenneth Bock's book was really helpful in discussing how different people manifest these issues in different ways, though to be honest, I'm not really sure how, long-term, my daughter would've manifested this stuff, it's not crazy numbers of allergies, she's only got 2 intolerances, and it's not ASD/SPD behaviors.
A lot of the stuff you mentioned sounds like adrenal issues, and for twitchiness, I'd think magnesium. A lot of mercury people are low in magnesium, but again, and this is the worst part, zinc and magnesium deficiencies are the two most common mineral deficiencies around, and they're both fairly typical at some low level (or not so low level, in our case).
Be interesting to see blood results from today given that you've so recently had symptoms, I wish Panserbjorne were around, she'd really know how long mercury from an acute exposure will continue to circulate. I've seen different numbers.
For me, putting together a timeline of health things really helped. Every little thing, like getting glasses and my (relatively minor) dust/pollen/dog fur allergies starting, my anxiety (which wasn't debilitating), like that.
And try to think back to when your adrenal issues started, if you can see any changes there. Because there's got to be a reason your adrenals are fatigued, if not your amalgams, then something. It takes a while to think about, even with prodding I've had to re-think a few times, and I've put together bits and pieces a while after I started.