A Rant: (Bear with me)

My psychiatrist has diagnosed me three times at three different appointments, each in a frighteningly short amount of time. I was referred by my doctor because of how complicated my major depression was. That appointment she agreed with my first doctor and increased my dose of my already prescribed anti-depressant. On my second (or third) appointment she told me that I seemed to have 'bi-polar tendencies' that she was concerned about. She added an anti-convulsant to my regime to help ensure I did not swing into a full manic episode. At this point I felt this was all very reasonable BUT was concerned at how fast she would diagnose and treat. She had not known me for any more than three sessions (so MAYBE 1.5 hours) and she was giving me a drug that has very serious rare, but real, side effects. A month later, still convinced of her diagnoses of Major Depression with Bi-Polar tendencies, she added another anti-depressant to offset the negative side effects of the first one as well as to raise my dose in general. Not a month later, when I felt another increase was needed she started discussing with me Borderline Personality Disorder. Convinced that this is what I had she said that therapy would work better to treat it than drugs and so would not increase my dose. I asked her why I was on drugs at all then and she said it wouldn't hurt so might as well stay on them as they may end up helping.
I didn't see her for about three months as she felt my therapy would be a better resource. When I did go back and discussed the problems I was having she uped my dose of the first anti-depressant. My check up appointment 2 weeks later I told her about the hypomania I was experiencing because of this change - she added an antipsychotic to help. When these where highly sedating to the point i was so drowsy i couldn't function at work, she decided I needed a different brand. I am starting those today after I go for blood work as these have a risk of increasing something in my blood (cant remember what) that can potentially be very harmful. She wants to get a baseline measurement of my levels of this components so it can be monitored.

What the fuck!? It really pisses me off, and worries me, that her seemingly baseless 'diagnoses' give her the justification she needs as a doctor to give me mind altering drugs that all have side effects, minor and severe. I am not saying that I do not appreciate what she is doing, because I do, and I'm glad to have a doctor who specializes in these drugs so i have the best chance of having a stable and functioning life but common! I know that in the future Dr's and patients will all look back at these practices with horror (as every generation has - lobotomies use to be common practice and now we are appalled by such treatment). Essentially the treatment I am undergoing now is the class shot gun method: "because we do not know exactly how drugs like these work, we will see how they effect you and then adjust from there... okay you seem to go a bit manic so we will add this...we will see what happens now..."
I feel like I am a tower of china. Imagine someone who is trying to stack all the china in their house; it wobbles and sometimes they have to hold their breath hoping it wont fall; when they think they are finished they walk away slowly so as not to disturb the tower but inevitably it begins to falter so they take off the most problematic pieces and think of a different strategy for adding them to the construction.
Do the limits of our knowledge for the treatment of mental illness mean that we are always bound to fall?