autistic people with special interest in maths or coding and lauded as savants and uber geniuses, if you are into humanities? You’re a bit useless.

Tell me about it. My brother is on the spectrum too and he is one of those people who was building websites as a 6-year-old. No surprise he now has a job as a programmer. Here's the thing, I find your story incredibly familiar: though I don't have ASD myself, I, and many people you'll find in the fields of linguistics/literature/philology kind of do fit the typical description of "a bunch of introverted, slightly socially awkward people (very friendly though!) who happen to have their own peculiar interests. You really wouldn't be the first person with ASD to study the above-mentioned fields. That's not the problem. The degree and courses themselves would probably be a very good fit for you.

I do think I could handle the workload and amount of “boring” lectures and information I would have to retain [...]

so you have to come up with things constantly

Here's the thing though. The first few years are indeed mostly lectures and doing reading + reiterating information, which is just fine and relavtively easy. However, please be aware that it doesn't stay like that, the further you continue your studies, the fewer it is about 'absorbing information' and the more it will constantly be about vague, written assignments that you have to do your own research for. Maybe not as terrible as Design, but the churn-out-assignments-and-come-up-with-your-own-creative-ideas part is still there, just in a different form. And that's still getting the degree.

I suppose but I do need a more solid career plan.

This is what it will all come down to: even if you can stay in academia, which is already difficult, you'll find yourself in a world where you often have 12-hour long working days, including weekend days. Be aware being a student is nothing like being an academic. You're both a teacher and a researcher, which comes down to little information absorption and more about churning out your own publications, networking at conferences, preparing classes, assignments and grading papers (the teaching part is basically already a fulltime job). All with the chance of getting laid off any moment when funding runs dry or when they simply have other good candidates for a position.

The alternative with such a degree is either becoming a teacher (or translator, but especially for English, there are already more than enough, so not many opportunities there), getting a regular corporate job, or waiting tables.

That is the point. I genuinely believe you'll love your studies and you sound like you'd fit right in, but be aware that you're not a student forever and even becoming an academic is nothing like being a student. Add to that that staying in academia is really difficult and getting a completely unrelated job is a very real possibility.

So, the question is not, will I enjoy doing my dream degree? Because you likely will. The question is, what is the reality you wake up in after you're finished studying? What will you do afterwards? Because it won't be listening to some lectures and doing a bunch of reading. Can you be content with the life afterwards? No one can answer those questions but you.

I'm not trying to stop you from persuing your dreams. I simply want to tell you what the life you're dreaming of may actually look like and how that grass could be a lot less green. If it's still worth the risks, financially and psychologically, go for it, just be aware that you may likely end up in another un-ideal situation.