I'm sensing hostility in your answer, and I'd like to help try to alleviate the "negativity," but I don't know if it will work.
I'm someone who is usually quite comfortable in social situations, and I'm also quite at home in most surroundings, although there are exceptions for all of us.
My therapist explained to me that many people on the spectrum experience anger about (or within) their issues. I've never felt that way, but I have interaction with a few others on the spectrum who always speak in an aggressive manner.
Sometimes, people will react to your tone, rather than what you say. EVEN if what you say is perfectly accurate, they way in which it's presented can be mistaken.
Part of socialization is learning how to react to others. Many on the spectrum (especially those with few visible social skills) hear the message, but not the intent.
I admit that I do that, as well. If someone contacts me via text or e-mail, and doesn't speak to me directly, I always tend to be "on the defensive," when reading the communication. It's usually not intended to be received the way I "heard" it in my head, but I immediately go to the "worst case scenario."
If someone speaks to me in person, and I can hear their voice/tone and watch their facial expressions, I am usually relieved to learn that it was a misunderstanding on my part that made me feel frustrated (I don't use hate or anger, because they are reserved for very few people).
That being said, from my background, training, and upbringing with parent(s) who were very possibly on a lower level of the spectrum than myself, I needed to find a way to express exactly what I meant, and wouldn't be taken the "wrong way."
When I discovered (thanks to great teachers) that I had a natural ability to write (I think a teacher told me I wrote the most convincing Collection Letters), I decided to do that.
As a writer, I've learned how to "describe" situations so that most anyone who reads or hears my words understands what I'm saying. Often, especially in Q&A forums, my posts are quite long, because I "explain" the reason for my answers (usually).
They get wordy, just like this. So, your therapist will help you to determine exactly what caused the meltdown and how you might be able to foresee an occurrence in the future. It's possible that you'll have things to remind yourself to stay focused, or can do to calm the situation.
Therapy is not just about pushing you to be social, but how not to let things upset you enough to cause a meltdown.
One of my social anxieties is that I hate speaking on the phone (unless there's someone I obviously want to talk to). I know *how* to use the phone, I teach others how to use the phone, and when I'm on the phone with someone I'm polite, respectful, and I know how to get things done (if it's a professional call).
One therapist decided to "force me" to make a call to someone while I was in his office (just to motivate, I guess). He seemed surprised that I handled the call with no difficulty whatsoever. I had to repeat to him that I know HOW to make a call, I just don't want to.
If you don't want to socialize, you don't have to. But wouldn't you rather at least be "less upset" about things? I have never experienced (personally) being upset all the time, unless it was something extremely personal. But, I welcome people into my circle whether or not they care to socialize.
Just be yourself, and do what you want, but therapists have a way of helping us calm down that others just can't do (any most of them really do care about their patients).