Hi Andy,
I was just reviewing
Yasko's Vimeo video on CBS and noticed that she said that B6 (P5P) increases CBS activity. This would cause any methyl groups to go shooting down the CBS drain. So you would actually want to mostly limit your intake of P5P. (a little bit is apparently desired). So if the methyl groups are shooting down the drain, they won't be available to make neurotransmitters, thus depression.
I'm not sure about the phosphatidylcholine or zinc, but it sounds like you're just not ready for them yet or you're possibly taking too much.
It really sounds like CBS is an issue for you.