not being able to look people in the eye is yet another symptom of asperger's, which is highly correlated to autism which is highly correlated to mercury poisoning which is highly correlated to every single symptom you have reported, right down to the problems with methylation.
ramping up methylation in the case of mercury toxicity forms a substance called methyl-mercury which is an order of magnitude more toxic than mercury. this is why mercury toxic people have paradoxical responses to vit b12.
if you are extremely clever you may be able to dig yourself out of this hole with some some sort of methylation trick. it will have to involve the complete conjugation and excretion of bile from the liver and gall bladder. if you do not have proper bile flow you will get worse and worse.
one of the cheapest/easiest ways to ramp up your methylation is to eat beets. beets are also, and probably not coincidentally, one of nature's best foods for thinning bile and resolving gall bladder issues. to give it a thorough trial i would say to consume 1 large beet per day or 4 ounces of beet juice for 2-3 months. if there is no resolution after this point then another course of action would be in order.