It's taken me years to see through all the various one-element
approaches to fixing this or that symptom
The problem does not lie with the "one element" approach. As you pointed out you were megadosing, which is the problem. Megadosing on specific compounds can cause imbalances in other compounds. If taken properly then supplements such as zinc or B vitamins are not really an issue. They are called supplemental because they are supplemental to the other nutrition you get in your diet. They are not substitutes for diet. They just fill in for certain deficiencies in a diet. For example a person with type 2 diabetes is going to be deficient in chromium as it has been refined out of the food most people eat. Asthmatics tend to be deficient in magnesium, again not that common in most people's diets. Supplements can help fill in these blanks, but again they must be used properly. If you drank 5 gallons of water in a day and died from your brain swelling would we blame the water and say water should be avoided because it caused an imbalance? No, you would be blamed for not using something beneficial properly. Supplements are no different.
Herbs like nettles and alfalfa, horsetail...
I love nettles and alfalfa, but horsetail grass (shavegrass) is a different story. Horsetail contains nicotine and is a vasoconstrictor. This makes it a really bad idea for anyone with circulatory issues such as diabetics, those with congestive heart failure or arteriosclerosis, those with Raynaud's disease or Raynaud's phenomena, etc. This is why I never recommend it.
That's so interesting. The very same guy who told me that I had arteriosclerosis, told me to drink horsetail tea three times a day, which I did for a few weeks, but I just didn't enjoy it, and so I went back to drinking yerba mate.
He was on the right track since silica will help prevent arteriosclerosis. But there are much better choices. Purified diatomaceous earth is the best as it is pretty much pure silica. Herbally bamboo is the highest herbal source of silica. It is seven times higher in silica than horsetail and unlike horsetail bamboo dilates the blood vessels. Nettle is a great source of silica, vitamin C and sulfur all of which are excellent for the blood vessels. It also supports the adrenals, liver, kidneys and thyroid. Seaweeds have a long history of being used to treat arteriosclerosis. A lot of this is due to the silica content of seaweeds.
Look into chaga.
I take it you are referring to chaga (black conch) mushrooms? If so these are great. Up to a few years ago noone seemed to know what they were. I had only known two people that had a clue what they were. An herbalist in Santa Cruz, California and a Lakota medicine man. There area couple of places up North where there are large sections of them so I would go collect them when I was up there. They only grow on birch trees where they suck up the betulinic acid from the tree bark and concentrate it. Betulinic acid is an extremely powerful antiviral and anti-cancer agent.