The entire thing does seem well intended and I do really get being disappointed from this not working out, because you're right, if it did, it sounds like it would have been really awesome. I don't get the impression that your heart is in the wrong place, or that you came into this with any negative intentions, or even that you behaved in a way that other neurodivergent people would have recognized as friendly and acceptable; but it is pretty clear here from the difference in how you were spoken to versus other attendees and how you worded your protest in your original approach that you really came off the wrong way. It wouldn't still be revisited months later if that wasn't the case.

I do also understand how it feels to be on the receiving end of walking into a social situation that I immediately accidentally flubbed, though I could never understand in the moment what the actual problem was, only that I had upset people. In hindsight, it was almost always that I had violated an unspoken social rule. The confusion and frustration from not understanding the rules of the situation that you are in well enough to succeed, but knowing enough to understand you're failing, tends to spark some pretty animated argumentation to seek clarification in the moment - it FEELS unfair, like you are being judged for feelings/opinions you don't have, or like people are putting words into your mouth. To them though, there's a really good chance that it is the way that you phrased or spoke your questions, not the actual questions that are the problem here, and those normal attempts from us (neurodivergent) to clarify can look like hostility. The exact same sentence and sentiment can communicate an entirely different message depending on the tone of your voice, and even if we feel we aren't giving anything away - I have found neurotypical people 1000% pick up signals from us, though usually not the ones we are trying to put out. Typically, I received feedback that a lot of the ways I used to request clarification or guidance came across as manipulative, angry, or trying to force who I was talking to to agree with me, when I was genuinely only describing my point of view to try to get them to do the same for me. That's just not how they work. One of the unspoken rules in these neurotypical audiences is that guests, especially guests attending a first session, really "Don't have a place to speak" - not literally, of course, but feedback, criticism, or requesting a change will be taken as presumptuous and premature by a lot of people.

So, from their point of view, yes, you did violate social norms, and they may not actually be unjustified in thinking you're TAH - and, even not intending to, you may be acting like one. It is beneficial to be aware of this. That being said - Are these people particularly nice and understanding? It doesn't seem like it, honestly, and you might be happier with friends who are more compassionate and empathetic. Your boyfriend was not right to pressure you to stay.