Don't try to tell an "authentic" story. Instead, tell an "inauthentic" truth.
Let somebody else write only allistic characters. You can write a character who is probably, or maybe, on the spectrum, but this does not need a huge reveal or internal struggle—it can just be a thing you do, among other things you do, as an author.
The author's surest path to reader satisfaction is deliberately picking an approach and then flagging it early on so readers know what to expect.
As with writer's block, what's getting in the way of self-promotion is not practical but psychological.
In first-person POV, it's challenging to convey who's speaking without a clunky or clichéd paragraph of self-description.
I love the idea of a beta reader dating service! And in fact such things exist.
Adding or subtracting a character in the middle of creating a lengthy work is nearly as challenging as breaking up with a longtime life-entangled partner.
You already made your work in the best way that you know how. Now you need editorial advice. That's part of the process for any writer, and being an editor in no way exempts you from it.
There are some projects where artistic urges outweigh commercial considerations, and this sounds like one of those.
The way you feel isn't a rational response to a defined situation, and can't be evaluated on that basis. Feelings don't stay contained and orderly. Some of your feelings may not even be about your writing.