I am a social worker and do work with people on the autism spectrum as well as other disabilities. There is a huuuuge debate about what "disability" even means. The conversation in moving away from thinking of "disability" as something inherent to the person with for example medical issues and more over to seeing society as the factor that disables/handicaps people. Which is why becoming more accommodating for people with different needs is so important. The conversation is really relevant and everyone is coming to different conclusions, the example of the deaf community came up.
This is also why more and more special programs are popping up to get people with disability help in the job market.
That aside, with autism it really really depends on the severity. I personally do work with a person diagnosed with Aspergers who needs supervision (living in a residency) and couldn't handle the stresses of a typical job. I would not really consider him "disabled" but he definitely is not able to live a "normal" life, which in it of itself is not a bad thing. That's not saying this applies to you, I just want to be clear about where my opinions are coming from.
I think you already have a pretty clear grasp on your problems, be they because of autism or not. And you are handling your life well without a diagnosis. It is not necessary for you to get it, but I would still advice to do so. It would open your access to certain resources which you can then take or leave as you please. You already said it, people with autism can learn social skills as much as anyone, but people tend to be really stupid in explaning them. People without autism just kinda assume you get it, because that's how they did it.
I totally understand being a afraid of a stigma und not wanting to be the "special case" in your workplace. That's 100% your decision to make. A lot of people can be assholes and might be. But from my experience it can help other people understand what's going on and just be a bit more relaxed and even attentive if they know (I suffer from depression and let my coworkers know, when I'm having a bad day). I think it's a god thing that workplaces are more accommodating now and it is not a bad thing to realize you might have different needs from others, while still killing it at the job.
Thing with disability is: a person in a wheelchair would not pass up a job opportunity because there was a ramp for him and he thought he should be able to walk up there. And a job with special accommodations for people with autism is the same essentially. Just a ramp for the brain sometimes to reduce certain stresses.
But yeah, you don't have the diagnosis yet, so maybe start there (or not) and figure out the rest on the way. Might be helpful to know for sure. Weather or not you choose to do it, you have been doing good in learning and adapting with friends from what you wrote, so that's awesome.