I would not recommend an antipsychotic like Stealazine for anxiety/jitteriness as even psychiatrists are typically not prescribing it unless you show strong psychosis/mania symptoms. The side effects from these medications are strong, often much worse than something like overmethylation, which is speculated whether it even exists. CFS/ME patients tend to react badly even to milder psychiatric medications like SSRI's.
"Long-term use of trifluoperazine can cause a serious movement disorder that may not be reversible. Symptoms of this disorder include uncontrollable muscle movements of your lips, tongue, eyes, face, arms, or legs. The longer you take trifluoperazine, the more likely you are to develop this movement disorder. The risk of this side effect is higher in women and older adults.
Stelazine is not recommended as first line therapy in patients with non-psychotic anxiety disorders, nor should therapy be carried out for more than 12 weeks."