You are using a very slippery definition of "mental health" here. You are at risk of going full Moonbeam.
In any case, the treatments for 'mental health' conditions, even defined much more restrictively than you are doing here, are really not terribly effective. The whole topic is not very well understood, even if some people sometimes pretend otherwise. But you seem to be using it some fuzzy sense of "making human beings behave in a completely rational and moral manner at all times".
It is rather sad that a person so well informed about the problems attendant to the issue of mental health should actually have a drawn a bigoted and ultimately ill informed opinion based on your own personal bad experience. In the first place people seek psychotherapy not to get better but to become better at being sick and most therapist are attracted to the field because of their own mental illness. It is likely also that many are there for the money and are as jaded about life as you seem to be.
Given the above, the mass denial that self hated is almost universal and definitely true in your case, it is no surprise that very few become completely healed. In your case you were misdiagnosed at great personal suffering so now you tar and feather what strikes you as the cause, the mental health industry. I find you to be arrogant in the disparagement of a field in which, despite the flaws in patients and doctors alike many find better ways to see the world. Stop being an arrogant asshole. A rotten apple spoils the whole barrel. Don't be that person. You have likely never met a person with real knowledge. The risk you face going full Moonbeam is just a projection of the fear you would have to face to become more like me. You happened to have run into somebody who knows a few things you do not and your ego can't handle it.
I love your negativity for the insight it brings you. It's just too bad you let it get you down. It would help you to know that what you see in the world is how you feel about yourself and because the world is full of people just like you it makes it very real. But not everybody is unaware that what they feel only makes the world look like it does when in fact everything is absolutely perfect. There is only love. Be kinder and wake up. You were always OK before you got stuffed full of conditioning.