Interestingly, I found myself abnormally susceptible to the psychedelic effects. When taking ketamine orally, the expectation is that most of the medicine is absorbed while you hold the troch in your mouth for 30+ minutes. After a lot of experimentation, I found that I barely absorb any medicine through my mouth, but once I swallow it I absorb it very rapidly. This made it difficult to control the delivery speed, and likely hindered my treatment.
I haven't been dealing with depression for anywhere near as long as you, but I do speak from experience about how terrible it is to not find anything that works. I've gone through ~13 of the most commonly prescribed drugs for depression, anxiety, and sleep, and none brought any relief. I've now tried and failed out of ketamine, which I was really hopeful for. Now I'm just back to sitting around trying to get _any_ doctor to actually see me and maybe get tested for various neurodivergent conditions.