We really only have one amazing piece of technology at our disposal: statistics. At the absolute best (and I'm not saying it's always the best...), what comes out of a pharmaceutical development pipeline is a drug that works for some people some of the time. Sure, sometimes you get broad categories to try to narrow down effectiveness, but at the individual level there is ultimately no choice but to try a drug and see if it works. And this is especially true in psych drugs, in no small part because there are so many unanswered questions about how our mind works.
And that sucks. I get it. It must be so frustrating to deal with a revolving door of new regimens and new side effects, all while yearning for relief from the underlying ailment. Not to mention navigating our nightmarish medical bureaucracy. But please understand that doctors, generally, are just doing their best to help given the tools they have. If you don't currently have that kind of trust and partnership with your doctor, I hope you are able to find one with which you can. I wish you the best, and hope that this perspective will make your frustrations somewhat easier to bear.