Hey DJ Shaka - I hope you are getting on well, now. I had a similar (well, not similar but) I absolutely thought that it was a dangerous technique, really dangerous and I think the lack of awareness of the ATs is almost criminal. When people are going through a severe psychosis their input is "stay a few days longer". Yeah, right.
If they actually had any psychiatric qualifications they would be disbarred for malpractice. As it is of course they don't, so they just repeat what they have been told to say, ad infinitum... really bad, I think. They are not trained and it is an invasive technique, messing with people's minds, they will not react to you as an individual with a set of psychological issues unique to you, no they will just repeat the same old line. Hopeless and, as you say, dangerous. There should be more made of this fact, absolutely.
How are you coping now? How is your anger? Don't let this control you, it's not worth it. I agree absolutely with one of the previous posters who said, bring it down a whole notch --- do some very grounding stuff, hang on with friends, laugh (really important, I think), have fun I don't know go skiing or something totally different, eat with groups of friends in a mountain restaurant after falling on your backside for hours trying to learn how to ski --- it is a good way to get all that nonsense out of your system.
As to whether it is brainwashing, in my opinion it most certainly is and Goenkaji laughs that off anyway "well, perhaps your brain needs to be washed" Humph! And yours Goenkaji?

Here is a little article on brainwashing:
Persuasion and Brainwashing Techniques Being Used on the Public Today is a fascinating article by Dick Sutphen about, well, how persuasion and brainwashing techniques are being used on the public today by religious organizations, the military, human-potential organizations, and the media.
It’s a long article so I’ll paraphrase the six techniques here:
1. Isolation: the meeting or training takes place in a place where participants are cut off from the outside world. This often involves making a public commitment to stay during the training. When training takes place in isolation like this, there is usually a quick follow-up session to ensure that the technique has really taken hold.
2. Fatigue: a schedule is maintained that ensures physical and mental fatigue. This means long hours, few breaks, and very little time for relaxing or reflection.
3. Tension: techniques are used to increase tension in the group. For example, perhaps there are a few truisms thrown around that might make you feel like you are doing something wrong. Or that you are a sinner, or depressed, or generally unhappy.
4. Uncertainty: people are randomly put on the spot. Forced to withdraw into anger, fear, or awe. Revivalist churches and human-potential seminars include asking people to come on stage and talk about humiliating or weak moments in their lives. This withdrawn, fearful, state, makes you many times more susceptible to suggestions as your guard is down and you are looking for safety and reassurance in whatever form it takes.
5. Jargon: new language to talk about what’s going on. It could help label the “enemy”, whether it be ignorant people, people who aren’t yet enlightened, or evil people. Also, new language to talk about people who are “fixed”: either enlightened, saved, or healed.
6. Humorlessness: there’s no humor involved until the process is complete. The humor then serves as a way to celebrate and seal the deal.
A couple other techniques can be used in addition to help the effects become more pronounced. These three steps are called the “decognition process” as they help slow down and eventually stop thinking altogether.
1. Alertness Reduction: one part of this is to force participants to keep a poor diet: either lots of sugar, or very bland foods. Sugar throws your nervous system off. A very bland diet (usually fruits and vegetables and no dairy or meat) will make you more spacey. Another part is inadequate sleep after long hours of intense discomfort or strenuous physical activity.
2. Programmed Confusion: a deluge of new information, combined with questions, discussion groups, and one-to-one create a sense of jumbled-ness that make it easier to insert crazy ideas.
3. Thought Stopping: most of these brainwashing techniques encourage stopping your thoughts in one of three ways. All three processes can be very helpful if you are controlling the process. The only danger comes when you allow someone else who you don’t fully know the motives of to take you through these steps and slowly alter deep beliefs about yourself and the world.
1. Marching to a beat, usually at around 1 or 1.5 steps per second, is particularly useful. Both the military and Hitler used this to great effect. The beat puts you in a slightly altered state of awareness that is close to hypnosis and makes you more susceptible to suggestions.
2. Meditation is the second form of thought stopping. An hour to an hour and a half of meditation a day for several weeks is enough to keep you in a constant “slow” state that is more focused and susceptible to suggestions (both good and bad).
3. Chanting is the third form of thought stopping, and has the same general technique as marching. The beat helps put you in a slightly different state of awareness.
Sound at all familiar?
That said I don't want to get you worked up again, it's OVER. It's done and as the other poster said, it may take a while but you will come back to yourself.... don't let the anger be a habitual thought pattern starting. Every time you feel angry think of something that you LOVE whether that be your child (or any loved one) a favourite memory or whatever it might be... Good luck. I am so sorry you had a hateful experience, I did too. I really did. It happens.
Some of us are not happy to be brainwashed, that's it and ya know, that's also a good thing. Otherwise we would all fall into step with some of the most horrific charismatic orators around (viz Hitler and the rest). It is a good thing and it means you are a strong person.
What makes me most convinced that it is a brain washing cult however, is the reactions of the majority of those who are "fans" to criticism. It is unnatural. The level of personal outrage and defensiveness it engenders - as if you had slandered their very soul! Why so defensive, why so over-sensitive? If you were to criticise something else they do, maybe a Pilates class and say it didn't work, it put my back out --- the reaction of most would be "Oh no, that's dreadful, poor you" rather than "Don't slander Pilates, you just weren't doing it right! You didn't understand the technique. It is all great and by saying this you will (gasp) put people off, that's dreadful, you are doing a dreadful thing".
It is absolutely peculiar the reaction of past students and from that, especially, I take away the fact that they must have been brain washed. Otherwise why react so intensely, so personally, so out of all proportion?
I do wish you well, from a fellow sufferer!
All the best - btw there is a great tape blog by someone who suffered a psychosis after a Vipassana retreat, he is the funniest, humblest, most charming guy (you just hear his voice on the tape) if I can re-find the link I will post it for you, because it is lovely. He was based in New Zealand but has a faint Irish accent, I would say. It is great - although salutory, it took him many, many, many months to recuperate (years really I guess but that doesn't mean it will be the same for you).
I can't find the link right now - my googling skills are not all that! If I find it, I will post it because it is great. Charming, open, honest and really worth listening to, or at least it was for me, very nice to hear someone speaking so directly about their experience.