confused about autism

Not sure should I do this in the introduction forum or not, but oh well. For some time now i've felt I might be autistic. I do have neurodivergence as I have ADHD, but i'm not so sure any more that that's all it is. I still can't figure out what is the pure defenition of autism, as many of any online tests atleast are very stereotypical and I can't figure out how that specific symptom could look different in myself.

Some things that has made me wonder if i'm autistic:

- people annoy me often, because I feel they make no sense sometimes, like some questions are very annoying to me, for example listing things, like listing what do i like about minecraft, it makes me uncomfortable to list things bc I don't understand why and if I say "I like building" it feels like i'm saying I like only building, and I can't possibly list EVERYTHING that I like about minecraft.

- apparently strange posture is a symptom? and my posture is quite strange

- I "split hairs" and get stuck on "unimportant details" that for me are very very relevant and important to the subject/debate

- difficulty connecting with others, sensory sensitivity (clothes like long sleeves + jacket was horrible when younger, also socks, only I knew how to put them on correctly, FOOD was hell, my hair made me insane), pretty much every ADHD symptom but those can be explained with ADHD u know

- "how are you" annoys me, I don't get it, unless i'm doing very unwell I don't know how to anwser, I just am?

- apparently the need to keep things in order can be a symptom, I don't mean physical things I mean like I want to take a picture of all of my possessions like clothes and so I remember everyhting that I have and can keep track. also, journaling can go very overboard, it makes me anxious because I feel like I have to write EVERYTHING like what's happened almost. and journaling soothes me also bc my thoughts and memories are now saved and laid out

- apparently the way I organise physical things is kinda odd, like my desk at home, I put items in certain patterns or following certain rules, it's hard to explain

- overwhelmed sooooo often, but also ADHD symptom

- I like to keep earplugs on in public transport and the city bc it's way calmer that way

- kind of OCD behaviour without the feeling of "unless I do this something bad will happen" more like "I need to do this because I need to" like the need to touch the whole surface of a item or like a door handle, feels horrible if a spot is left untouched, this was "worse" when I was younger. I also had to visualise like for example water filling all of the space of like container that was more complicated than like a jar or glass

- when I was younger I had these intense waves of empathy, like, INTENSE

- alot of what people say annoy me. like if they're kind of incorrect about something or make contradictory statements, nobody else seems to mind. but it's very important to me that the things people say are correct, and I get stuck on those things, everybody else seems to understand that their statements were not so absolute, it makes me very annoyed though

- probably alot more but i'm tired

I don't have problems understanding humour or sarcasm, i'm very sarcastic and funny myself, but apparently thats not even the case with all autistic people

I could use some  unprofessional opinions or sharing of experiences so I can help myself figure it out!