SAMe can be quite helpful as glutathione boost and supports liver function/detoxification. It does support mood, if it helps you. 1,600 mg/day is considered the therapeutic dosage. Purchase via an online retailer is the only affordable way to buy it, and good prices are out there.
TMG is recommended in conjunction with it, as are some B vitamins. If you have methylation issues, TMG would be easier on your body than taking a form of the B's that might not work for you.
Look into cofactors related to histamine. Have you looked into methylation issues?