An alternate explanation might involve leaky gut and a peptide called cholecystokinin (CCK), which is involved in the digestion of fats and protein through the release of bile from the gallbladder and digestive enzymes from the pancreas, respectively. According to
Encyclopedia Britainnica "[CCK's] secretion is stimulated by the introduction of hydrochloric acid, amino acids, or fatty acids into the stomach or duodenum."
So we have a peptide whose release is triggered by, among other things, HCl in your stomach and duodenum. But how does this cause a panic attack? According to
John Brisson
A single CCK peptide known as CCK-4 is to blame.
18 In someone that is healthy, most CCK peptides are broken down effectively in the digestive tract, or do not cross the BBB easily. When someone is having fat digestion issues, upper gut infections, SIBO, or leaky gut, CCK peptides are more likely to cross the BBB (specifically CCK-4.)
19 20 What does CCK-4 do when it gets into the brain? It overstimulates the vagus nerve for one and induces panic.
21Studies show that CCK-4, injected into the blood stream, causes panic attacks. It is quickly metabolized in the brain, so the duration of its effects are short, unless the act of panicking releases excess catecholamines which causes some people to have panic attacks for an extended amount of time.
22
For this theory to hold water we have to assume that you have some new kind of problem with gut permeability.
For what it's worth, I have had issues with panic sensations following fat- or protein- rich foods in the past, although I usually fix those problems by doing something to increase HCl and improve digestion generally. I also have a vague memory of having experienced panic as a result of too much HCl as well...so maybe that happened.
In terms of treatment:
1. As I mentioned above, I have tried taking extra HCl, and this has helped me when I got a feeling of "undigested food" sitting around. Maybe this isn't the issue for you.
2. When this got quite bad for me I went to a Chinese Medical Clinic and got some herbs, that seemed to help. Because I didn't need to keep taking them forever, I assume that the problem they fixed was dysbiosis-related--but I don't know.
3. Any of a whole lot of leaky gut remedies like licorice root tea, Saguna Silicol Gel, glutamine, quercetin, et.
To be honest, I feel like even if this theory is mostly right, we might be missing a piece or two to explain exactly why 3g of Betaine-HCl is suddenly the wrong amount, or else why your gut is suddenly much more permeable. Did you get an infection that effects your GI? Do you have a new food allergy?
Taking a step back, I also wonder if there isn't some unknown factor that can cause a higher proportion of CCK to become CCK-4, or else cause CCK-4 to resist cleavage. For example, are the enzymes involved in cleaving CCK-4 sensitive to pH? Or is undigested food more acutely irritating to the gut lining than I had thought?
Finally: I somewhat obviously prefer the CCK theory to the methylation-causing-magnesium-depletion one, but I might have an imperfect test for the Mg-centered theory: Try taking dimethylglycine-HCl (DMG-HCl) It is more or less a methyl sponge, but it still contains HCl. If it causes a panic attack similar to before, then you know that the problem is not overmethylation. Unfortunately, if it does not cause a panic attack then you are left with the question of whether that was because it did not overmethylate you or because DMG-HCl stimulates less HCl secretion than TMG-HCl (thus triggering less CCK release).
@Deltrus: Although I disagree with you today, I am open to being proven wrong, and I look forward to seeing what you come up with regarding Mg and ME/CFS. In regards to ways to keep Mg in our cells: You may already be aware of the link between selenium and Mg, but if not you might want to see what I wrote about it
here. Best of luck sleuthing out a fix to this illness of ours.
PS. Particularly because I mention treatment, I should add that I am not a physician of any kind, and that I am just suggesting what has worked for me in the past and what I might do in your place.