I had virtually the opposite experience to you, including it for the sake of discussion. I'd tried most of the same list as you and had very little positive outcome (all over the counter items or meds that were easy enough to get by saying the right things in order to a local GP)

Through the period I'd experienced some significant lows that all met different criteria - extended depression, severe self harm and mutilation, social difficulties, drugs, alcohols, other unsavoury behaviour (not quite hookers and blow but close enough). Most of the chemical strategies weren't effective, or it was easy enough to discontinue them them shop around for something else a few weeks later.

In the end, I think I reached a point where I was genuine about change and engaged with a psychologist, and within a couple of months the outcomes were very apparent, and positive. Not saying its a good measure of anything either way, just a demonstration of another scenario I suppose.